Rafał Miłecki [Mon, 2 Jan 2012 07:41:23 +0000 (08:41 +0100)]
ssb: SPROM: extract each core power info
We already extract some basic info but it's incomplete, reads info
about the first core only. Used data structure doesn't allow easy
adding of more cores.
This patch adds new struct and array for storing power info. The plan
is to: switch all extractors (including the ones using NVRAM) to new
struct, switch drivers, then deprecate and finally drop old SSB fields.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Eliad Peller [Thu, 29 Dec 2011 12:41:39 +0000 (14:41 +0200)]
mac80211: check sta_apply_parameters() return value
Bail out if sta_apply_parameters() returns an error.
Signed-off-by: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Matt Carlson [Tue, 17 Jan 2012 15:27:23 +0000 (15:27 +0000)]
tg3: Fix single-vector MSI-X code
Kdump kernels leave MSI-X interrupts (as setup by the crashed kernel)
enabled. However, kdump only enables one CPU in the new environment,
thus causing tg3 to abort MSI-X setup. When the driver attempts to
enable INTA or MSI interrupt modes on a kdump kernel, interrupt
delivery fails.
This patch attempts to workaround the problem by forcing the driver
to enable a single MSI-X interrupt. In such a configuration, the
device's multivector interrupt mode must be disabled.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Pfaff [Tue, 17 Jan 2012 13:33:39 +0000 (13:33 +0000)]
openvswitch: Fix multipart datapath dumps.
The logic to split up the list of datapaths into multiple Netlink messages
was simply wrong, causing the list to be terminated after the first part.
Only about the first 50 datapaths would be dumped. This fixes the
problem.
Reported-by: Paul Ingram <paul@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com> Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings [Tue, 17 Jan 2012 07:57:56 +0000 (07:57 +0000)]
net: WARN if skb_checksum_help() is called on skb requiring segmentation
skb_checksum_help() has never done anything useful with skbs that
require segmentation. Setting skb->ip_summed = CHECKSUM_NONE makes
them invalid and provokes a later WARNing in skb_gso_segment().
Passing such an skb to skb_checksum_help() indicates a bug, so we
should warn about it immediately. Move the warning from
skb_gso_segment() into a shared function, and add gso_type and
gso_size to it.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yaniv Rosner [Tue, 17 Jan 2012 02:33:29 +0000 (02:33 +0000)]
bnx2x: Disable AN KR work-around for BCM57810
Disable the work-around for the autoneg KR of the BCM57810 in case the Warpcore version is 0xD108 and above, which fixes this problem.
Signed-off-by: Yaniv Rosner <yanivr@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yaniv Rosner [Tue, 17 Jan 2012 02:33:28 +0000 (02:33 +0000)]
bnx2x: Remove AutoGrEEEn for BCM84833
Disable the autoGrEEEn feature for BCM84833.
Signed-off-by: Yaniv Rosner <yanivr@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yaniv Rosner [Tue, 17 Jan 2012 02:33:27 +0000 (02:33 +0000)]
bnx2x: Remove 100Mb force speed for BCM84833
Remove unsupported speed of 100Mb force for BCM84833 due to hardware
limitation.
Signed-off-by: Yaniv Rosner <yanivr@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yaniv Rosner [Tue, 17 Jan 2012 02:33:26 +0000 (02:33 +0000)]
bnx2x: Fix PFC setting on BCM57840
This patch handles the second port of a path in a 4-port device of
BCM57840.
Signed-off-by: Yaniv Rosner <yanivr@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yaniv Rosner [Tue, 17 Jan 2012 02:33:25 +0000 (02:33 +0000)]
bnx2x: Fix Super-Isolate mode for BCM84833
The Super-Isolate mode comes to isolate the BCM84833 PHY from the
outside world. Not doing it correctly, made link partner see the link
before the driver was loaded.
This patch also involves SPIROM version fixes since it is used to
determine whether the common init of the PHY was already executed, and
the common init of this PHY is partially responsible for setting the
Super-Isolate mode.
Signed-off-by: Yaniv Rosner <yanivr@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
net: sh-eth: Fix build error by the value which is not defined
-----
drivers/net/ethernet/renesas/sh_eth.c:1706: error: 'pdid' undeclared (first use in this function)
drivers/net/ethernet/renesas/sh_eth.c:1706: error: (Each undeclared identifier is reported only once
drivers/net/ethernet/renesas/sh_eth.c:1706: error: for each function it appears in.)
make[5]: *** [drivers/net/ethernet/renesas/sh_eth.o] Error 1
-----
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> CC: Florian Fainelli <florian@openwrt.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings [Mon, 16 Jan 2012 12:38:59 +0000 (12:38 +0000)]
net: Use device model to get driver name in skb_gso_segment()
ethtool operations generally require the caller to hold RTNL and are
not safe to call in atomic context. The device model provides this
information for most devices; we'll only lose it for some old ISA
drivers.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Mon, 16 Jan 2012 04:35:50 +0000 (04:35 +0000)]
bridge: BH already disabled in br_fdb_cleanup()
br_fdb_cleanup() is run from timer interrupt, BH already masked.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> CC: Štefan Gula <steweg@gmail.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Glauber Costa [Sun, 15 Jan 2012 22:04:39 +0000 (22:04 +0000)]
net: move sock_update_memcg outside of CONFIG_INET
Although only used currently for tcp sockets, this function
is now used in common sock code (for sock_clone())
Commit 475f1b52645a29936b9df1d8fcd45f7e56bd4a9f moved the
declaration of sock_update_clone() to inside sock.c, but
this only fixes the problem when CONFIG_CGROUP_MEM_RES_CTLR_KMEM
is also not defined.
This patch here is verified to fix both problems, although
reverting the previous one is not necessary.
Signed-off-by: Glauber Costa <glommer@parallels.com> CC: David S. Miller <davem@davemloft.net> CC: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Fixing following sparse warning
>drivers/net/wireless/mwl8k.c:2780:15: warning: incorrect type in assignment (different base types)
>drivers/net/wireless/mwl8k.c:2780:15: expected restricted unsigned short [usertype] channel
>drivers/net/wireless/mwl8k.c:2780:15: got unsigned short [unsigned] [usertype] hw_value
Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Helmut Schaa [Tue, 17 Jan 2012 08:22:49 +0000 (09:22 +0100)]
mac80211: Fix possible race between sta_unblock and network softirq
All other code paths in sta_unblock synchronize with the network
softirq by using local_bh_disable/enable. Do the same around
ieee80211_sta_ps_deliver_wakeup.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Dan Carpenter [Tue, 17 Jan 2012 07:33:31 +0000 (10:33 +0300)]
mwl8k: fix condition in mwl8k_cmd_encryption_remove_key()
The intent here was to check whether key->cipher was WEP40 or WEP104.
We do a similar check correctly in several other places in this file.
The current condition is always true.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Alexandre Oliva [Mon, 16 Jan 2012 19:00:12 +0000 (14:00 -0500)]
brcmfmac: work-around gcc 4.7 build issue
Alexandre Oliva <oliva@lsd.ic.unicamp.br> says:
"It's an issue brought about by GCC 4.7's partial-inlining, that ends up
splitting the udelay function just at the wrong spot, in such a way that
some sanity checks for constants fails, and we end up calling
bad_udelay.
This patch fixes the problem. Feel free to push it upstream if it makes
sense to you."
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Hiroaki SHIMODA [Sat, 14 Jan 2012 07:10:21 +0000 (07:10 +0000)]
bql: Fix inconsistency between file mode and attr method.
There is no store() method for inflight attribute in the
tx-<n>/byte_queue_limits sysfs directory.
So remove S_IWUSR bit.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Some functions and variables in ehea are only used in their own file, so
they should be static. One particular function had a very generic name,
print_error_data.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Fri, 13 Jan 2012 22:58:42 +0000 (23:58 +0100)]
brcmsmac: remove PCI suspend/resume from bcma driver
The brcmsmac driver isn't a PCI driver any more, it's a bcma one. The
PCI device has been resumed by the PCI driver (the generic PCI layer,
really), we should be resuming just our own driver state.
Also add pr_debug() calls to show that we now actually get the
suspend/resume events.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
If there was a dumping error in the middle, the set-specific variable was
not zeroed out and thus the 'done' function of the dumping wrongly tried
to release the already released reference of the set. The already released
reference was caught by __ip_set_put and triggered a kernel BUG message.
Reported by Jean-Philippe Menil.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jozsef Kadlecsik [Tue, 17 Jan 2012 09:39:05 +0000 (10:39 +0100)]
netfilter: ipset: autoload set type modules safely
Jan Engelhardt noticed when userspace requests a set type unknown
to the kernel, it can lead to a loop due to the unsafe type module
loading. The issue is fixed in this patch.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Yoni Divinsky [Mon, 16 Jan 2012 13:18:59 +0000 (15:18 +0200)]
mac80211: fix tx->skb NULL pointer dereference
In function ieee80211_tx_h_encrypt the var info was
initialized from tx->skb, since the fucntion
is called after the function ieee80211_tx_h_fragment
tx->skb is not valid anymore.
Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fabio Estevam [Mon, 16 Jan 2012 02:47:12 +0000 (00:47 -0200)]
wireless: iwlwifi: iwl-scan.c: Fix build warning
Fix the following build warning:
drivers/net/wireless/iwlwifi/iwl-scan.c: In function ‘iwlagn_request_scan’:
drivers/net/wireless/iwlwifi/iwl-scan.c:572: warning: ‘cmd_len’ may be used uninitialized in this function
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Jesper Juhl [Sat, 14 Jan 2012 20:52:17 +0000 (21:52 +0100)]
Net, mac80211: Fix resource leak in ieee80211_rx_h_mesh_fwding()
We may leak the 'fwd_skb' we skb_copy() in ieee80211_rx_h_mesh_fwding() if
we take the 'else' branch in the 'if' statement just below. If we take
that branch we'll end up returning from the function and since we've not
assigned 'fwd_skb' to anything at that point, we leak it when the variable
goes out of scope.
The simple fix seems to be to just kfree_skb(fwd_skb); just before we
return. That is what this patch does.
Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Felix Fietkau [Sat, 14 Jan 2012 14:08:34 +0000 (15:08 +0100)]
ath9k_hw: fix interpretation of the rx KeyMiss flag
Documentation states that the KeyMiss flag is only valid if RxFrameOK is
unset, however empirical evidence has shown that this is false.
When KeyMiss is set (and RxFrameOK is 1), the hardware passes a valid frame
which has not been decrypted. The driver then falsely marks the frame
as decrypted, and when using CCMP this corrupts the rx CCMP PN, leading
to connection hangs.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: stable@kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com>
Rafał Miłecki [Fri, 13 Jan 2012 22:58:38 +0000 (23:58 +0100)]
bcma: invalidate the mapped core over suspend/resume
This clears the currently mapped core when suspending, to force
re-mapping after resume. Without that we were touching default core
registers believing some other core is mapped. Such a behaviour
resulted in lockups on some machines.
Cc: stable@vger.kernel.org Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
netfilter: revert user-space expectation helper support
This patch partially reverts: 3d058d7 netfilter: rework user-space expectation helper support
that was applied during the 3.2 development cycle.
After this patch, the tree remains just like before patch bc01bef,
that initially added the preliminary infrastructure.
I decided to partially revert this patch because the approach
that I proposed to resolve this problem is broken in NAT setups.
Moreover, a new infrastructure will be submitted for the 3.3.x
development cycle that resolve the existing issues while
providing a neat solution.
Since nobody has been seriously using this infrastructure in
user-space, the removal of this feature should affect any know
FOSS project (to my knowledge).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stephen Rothwell [Wed, 11 Jan 2012 00:52:17 +0000 (11:52 +1100)]
netfilter: xt_hashlimit: fix unused variable warning if IPv6 disabled
Fixes this warning when CONFIG_IP6_NF_IPTABLES is not enabled:
net/netfilter/xt_hashlimit.c: In function ‘hashlimit_init_dst’:
net/netfilter/xt_hashlimit.c:448:9: warning: unused variable ‘frag_off’ [-Wunused-variable]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Johannes Berg [Fri, 13 Jan 2012 13:17:59 +0000 (14:17 +0100)]
mac80211: fix no-op authorized transitions
When userspace attempts to authorize a station
that is already authorized, nothing happens as
you'd expect. Similarly, when it unauthorizes
a station that is associated, nothing happens.
However, when it unauthorizes a station that
isn't even associated yet, we erroneously try
to move the station to associated. This seems
to happen occasionally as a result of a race
when wpa_supplicant attempts to unauthorize
the port in managed mode. Particularly with my
new patches to keep stations, it can then move
a station into ASSOCIATED state before we have
really associated, which is really confusing.
I introduced this bug in
"mac80211: refactor station state transitions"
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Same devices can generate interrupt without properly setting bit in
INT_SOURCE_CSR register (spurious interrupt), what will cause IRQ line
will be disabled by interrupts controller driver.
We discovered that clearing INT_MASK_CSR stops such behaviour. We
previously first read that register, and then clear all know interrupt
sources bits and do not touch reserved bits. After this patch, we write
to all register content (I believe writing to reserved bits on that
register will not cause any problems, I tested that on my rt2800pci
device).
This fix very bad performance problem, practically making device
unusable (since worked without interrupts), reported in:
https://bugzilla.redhat.com/show_bug.cgi?id=658451
Reported-and-tested-by: Amir Hedayaty <hedayaty@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Gertjan van Wingerde <gwingerde@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Dan Carpenter [Thu, 12 Jan 2012 06:34:50 +0000 (09:34 +0300)]
ipw2x00: signedness bug handling frame length
This is basically just a cleanup. Large positive numbers get counted as
negative but then get implicitly cast to positive again for the checks
that matter.
This does make a small difference in ipw_handle_promiscuous_rx() when we
test "if (unlikely((len + IPW_RX_FRAME_SIZE) > skb_tailroom(rxb->skb)))"
It should return there, but we don't return until a couple lines later
when we test "if (len > IPW_RX_BUF_SIZE - sizeof(struct ipw_rt_hdr)) {".
The difference is that in the second test the sizeof() means that there
is an implied cast to unsigned.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
By adding some module aliases, programs (or users) won't have to explicitly
call modprobe. Vhost-net will always be available if built into the kernel.
It does require assigning a permanent minor number for depmod to work.
Also:
- use C99 style initialization.
- add missing entry in documentation for loop-control
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-By: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: David S. Miller <davem@davemloft.net>
RongQing.Li [Thu, 12 Jan 2012 22:33:46 +0000 (22:33 +0000)]
ipv6: release idev when ip6_neigh_lookup failed in icmp6_dst_alloc
release idev when ip6_neigh_lookup failed in icmp6_dst_alloc
Signed-off-by: RongQing.Li <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Fri, 13 Jan 2012 04:42:54 +0000 (20:42 -0800)]
Merge branch 'akpm' (aka "Andrew's patch-bomb, take two")
Andrew explains:
- various misc stuff
- Most of the rest of MM: memcg, threaded hugepages, others.
- cpumask
- kexec
- kdump
- some direct-io performance tweaking
- radix-tree optimisations
- new selftests code
A note on this: often people will develop a new userspace-visible
feature and will develop userspace code to exercise/test that
feature. Then they merge the patch and the selftest code dies.
Sometimes we paste it into the changelog. Sometimes the code gets
thrown into Documentation/(!).
This saddens me. So this patch creates a bare-bones framework which
will henceforth allow me to ask people to include their test apps in
the kernel tree so we can keep them alive. Then when people enhance
or fix the feature, I can ask them to update the test app too.
The infrastruture is terribly trivial at present - let's see how it
evolves.
- checkpoint/restart feature work.
A note on this: this is a project by various mad Russians to perform
c/r mainly from userspace, with various oddball helper code added
into the kernel where the need is demonstrated.
So rather than some large central lump of code, what we have is
little bits and pieces popping up in various places which either
expose something new or which permit something which is normally
kernel-private to be modified.
The overall project is an ongoing thing. I've judged that the size
and scope of the thing means that we're more likely to be successful
with it if we integrate the support into mainline piecemeal rather
than allowing it all to develop out-of-tree.
However I'm less confident than the developers that it will all
eventually work! So what I'm asking them to do is to wrap each piece
of new code inside CONFIG_CHECKPOINT_RESTORE. So if it all
eventually comes to tears and the project as a whole fails, it should
be a simple matter to go through and delete all trace of it.
This lot pretty much wraps up the -rc1 merge for me.
* akpm: (96 commits)
unlzo: fix input buffer free
ramoops: update parameters only after successful init
ramoops: fix use of rounddown_pow_of_two()
c/r: prctl: add PR_SET_MM codes to set up mm_struct entries
c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4
c/r: introduce CHECKPOINT_RESTORE symbol
selftests: new x86 breakpoints selftest
selftests: new very basic kernel selftests directory
radix_tree: take radix_tree_path off stack
radix_tree: remove radix_tree_indirect_to_ptr()
dio: optimize cache misses in the submission path
vfs: cache request_queue in struct block_device
fs/direct-io.c: calculate fs_count correctly in get_more_blocks()
drivers/parport/parport_pc.c: fix warnings
panic: don't print redundant backtraces on oops
sysctl: add the kernel.ns_last_pid control
kdump: add udev events for memory online/offline
include/linux/crash_dump.h needs elf.h
kdump: fix crash_kexec()/smp_send_stop() race in panic()
kdump: crashk_res init check for /sys/kernel/kexec_crash_size
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits)
pptp: Accept packet with seq zero
RDS: Remove some unused iWARP code
net: fsl: fec: handle 10Mbps speed in RMII mode
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c: add missing iounmap
drivers/net/ethernet/tundra/tsi108_eth.c: add missing iounmap
ksz884x: fix mtu for VLAN
net_sched: sfq: add optional RED on top of SFQ
dp83640: Fix NOHZ local_softirq_pending 08 warning
gianfar: Fix invalid TX frames returned on error queue when time stamping
gianfar: Fix missing sock reference when processing TX time stamps
phylib: introduce mdiobus_alloc_size()
net: decrement memcg jump label when limit, not usage, is changed
net: reintroduce missing rcu_assign_pointer() calls
inet_diag: Rename inet_diag_req_compat into inet_diag_req
inet_diag: Rename inet_diag_req into inet_diag_req_v2
bond_alb: don't disable softirq under bond_alb_xmit
mac80211: fix rx->key NULL pointer dereference in promiscuous mode
nl80211: fix old station flags compatibility
mdio-octeon: use an unique MDIO bus name.
mdio-gpio: use an unique MDIO bus name.
...
Kees Cook [Fri, 13 Jan 2012 01:20:59 +0000 (17:20 -0800)]
ramoops: update parameters only after successful init
If a platform device exists on the system, but ramoops fails to attach to
it, the module parameters are overridden before ramoops can fall back and
try to use passed module parameters. Move update to end of init routine.
Marco Stornelli [Fri, 13 Jan 2012 01:20:58 +0000 (17:20 -0800)]
ramoops: fix use of rounddown_pow_of_two()
The return value of rounddown_pow_of_two wasn't evaluated, so the
operation was a no-op.
Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cyrill Gorcunov [Fri, 13 Jan 2012 01:20:55 +0000 (17:20 -0800)]
c/r: prctl: add PR_SET_MM codes to set up mm_struct entries
When we restore a task we need to set up text, data and data heap sizes
from userspace to the values a task had at checkpoint time. This patch
adds auxilary prctl codes for that.
While most of them have a statistical nature (their values are involved
into calculation of /proc/<pid>/statm output) the start_brk and brk values
are used to compute an allowed size of program data segment expansion.
Which means an arbitrary changes of this values might be dangerous
operation. So to restrict access the following requirements applied to
prctl calls:
- The process has to have CAP_SYS_ADMIN capability granted.
- For all opcodes except start_brk/brk members an appropriate
VMA area must exist and should fit certain VMA flags,
such as:
- code segment must be executable but not writable;
- data segment must not be executable.
start_brk/brk values must not intersect with data segment and must not
exceed RLIMIT_DATA resource limit.
Still the main guard is CAP_SYS_ADMIN capability check.
Note the kernel should be compiled with CONFIG_CHECKPOINT_RESTORE support
otherwise these prctl calls will return -EINVAL.
[akpm@linux-foundation.org: cache current->mm in a local, saving 200 bytes text] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cyrill Gorcunov [Fri, 13 Jan 2012 01:20:53 +0000 (17:20 -0800)]
c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4
The mm->start_code/end_code, mm->start_data/end_data, mm->start_brk are
involved into calculation of program text/data segment sizes (which might
be seen in /proc/<pid>/statm) and into brk() call final address.
For restore we need to know all these values. While
mm->start_code/end_code already present in /proc/$pid/stat, the rest
members are not, so this patch brings them in.
The restore procedure of these members is addressed in another patch using
prctl().
Cyrill Gorcunov [Fri, 13 Jan 2012 01:20:49 +0000 (17:20 -0800)]
c/r: introduce CHECKPOINT_RESTORE symbol
For checkpoint/restore we need auxilary features being compiled into the
kernel, such as additional prctl codes, /proc/<pid>/map_files and etc...
but same time these features are not mandatory for a regular kernel so
CHECKPOINT_RESTORE config symbol should bring a way to disable them all at
once if one wish to get rid of additional functionality.
Bring a first selftest in the relevant directory. This tests several
combinations of breakpoints and watchpoints in x86, as well as icebp traps
and int3 traps. Given the amount of breakpoint regressions we raised
after we merged the generic breakpoint infrastructure, such selftest
became necessary and can still serve today as a basis for new patches that
touch the do_debug() path.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
selftests: new very basic kernel selftests directory
Bring a new kernel selftests directory in tools/testing/selftests. To
add a new selftest, create a subdirectory with the sources and a
makefile that creates a target named "run_test" then add the
subdirectory name to the TARGET var in tools/testing/selftests/Makefile
and tools/testing/selftests/run_tests script.
This can help centralizing and maintaining any useful selftest that
developers usually tend to let rust in peace on some random server.
Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Fri, 13 Jan 2012 01:20:41 +0000 (17:20 -0800)]
radix_tree: take radix_tree_path off stack
Down, down in the deepest depths of GFP_NOIO page reclaim, we have
shrink_page_list() calling __remove_mapping() calling __delete_from_
swap_cache() or __delete_from_page_cache().
You would not expect those to need much stack, but in fact they call
radix_tree_delete(): which declares a 192-byte radix_tree_path array on
its stack (to record the node,offsets it visits when descending, in case
it needs to ascend to update them). And if any tag is still set [1],
that calls radix_tree_tag_clear(), which declares a further such
192-byte radix_tree_path array on the stack. (At least we have
interrupts disabled here, so won't then be pushing registers too.)
That was probably a good choice when most users were 32-bit (array of
half the size), and adding fields to radix_tree_node would have bloated
it unnecessarily. But nowadays many are 64-bit, and each
radix_tree_node contains a struct rcu_head, which is only used when
freeing; whereas the radix_tree_path info is only used for updating the
tree (deleting, clearing tags or setting tags if tagged) when a lock
must be held, of no interest when accessing the tree locklessly.
So add a parent pointer to the radix_tree_node, in union with the
rcu_head, and remove all uses of the radix_tree_path. There would be
space in that union to save the offset when descending as before (we can
argue that a lock must already be held to exclude other users), but
recalculating it when ascending is both easy (a constant shift and a
constant mask) and uncommon, so it seems better just to do that.
Two little optimizations: no need to decrement height when descending,
adjusting shift is enough; and once radix_tree_tag_if_tagged() has set
tag on a node and its ancestors, it need not ascend from that node
again.
perf on the radix tree test harness reports radix_tree_insert() as 2%
slower (now having to set parent), but radix_tree_delete() 24% faster.
Surely that's an exaggeration from rtth's artificially low map shift 3,
but forcing it back to 6 still rates radix_tree_delete() 8% faster.
[1] Can a pagecache tag (dirty, writeback or towrite) actually still be
set at the time of radix_tree_delete()? Perhaps not if the filesystem is
well-behaved. But although I've not tracked any stack overflow down to
this cause, I have observed a curious case in which a dirty tag is set
and left set on tmpfs: page migration's migrate_page_copy() happens to
use __set_page_dirty_nobuffers() to set PageDirty on the newpage, and
that sets PAGECACHE_TAG_DIRTY as a side-effect - harmless to a
filesystem which doesn't use tags, except for this stack depth issue.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Nai Xia <nai.xia@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andi Kleen [Fri, 13 Jan 2012 01:20:35 +0000 (17:20 -0800)]
dio: optimize cache misses in the submission path
Some investigation of a transaction processing workload showed that a
major consumer of cycles in __blockdev_direct_IO is the cache miss while
accessing the block size. This is because it has to walk the chain from
block_dev to gendisk to queue.
The block size is needed early on to check alignment and sizes. It's only
done if the check for the inode block size fails. But the costly block
device state is unconditionally fetched.
- Reorganize the code to only fetch block dev state when actually
needed.
Then do a prefetch on the block dev early on in the direct IO path. This
is worth it, because there is substantial code run before we actually
touch the block dev now.
- I also added some unlikelies to make it clear the compiler that block
device fetch code is not normally executed.
This gave a small, but measurable improvement on a large database
benchmark (about 0.3%)
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: using prefetch requires including prefetch.h] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tao Ma [Fri, 13 Jan 2012 01:20:33 +0000 (17:20 -0800)]
fs/direct-io.c: calculate fs_count correctly in get_more_blocks()
In get_more_blocks(), we use dio_count to calcuate fs_count and do some
tricky things to increase fs_count if dio_count isn't aligned. But
actually it still has some corner cases that can't be coverd. See the
following example:
dio_write foo -s 1024 -w 4096
(direct write 4096 bytes at offset 1024). The same goes if the offset
isn't aligned to fs_blocksize.
In this case, the old calculation counts fs_count to be 1, but actually we
will write into 2 different blocks (if fs_blocksize=4096). The old code
just works, since it will call get_block twice (and may have to allocate
and create extents twice for filesystems like ext4). So we'd better call
get_block just once with the proper fs_count.
Signed-off-by: Tao Ma <boyu.mt@taobao.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Fri, 13 Jan 2012 01:20:32 +0000 (17:20 -0800)]
drivers/parport/parport_pc.c: fix warnings
drivers/parport/parport_pc.c: In function '__check_irq':
drivers/parport/parport_pc.c:3415: warning: return from incompatible pointer type
drivers/parport/parport_pc.c: In function '__check_dma':
drivers/parport/parport_pc.c:3417: warning: return from incompatible pointer type
Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 13 Jan 2012 01:20:27 +0000 (17:20 -0800)]
sysctl: add the kernel.ns_last_pid control
The sysctl works on the current task's pid namespace, getting and setting
its last_pid field.
Writing is allowed for CAP_SYS_ADMIN-capable tasks thus making it possible
to create a task with desired pid value. This ability is required badly
for the checkpoint/restore in userspace.
When kdump is loaded, kexec detects the current memory configuration and
stores it in the pre-allocated ELF core header. Therefore, for kdump it
is necessary to reload the kdump kernel with kexec when the memory
configuration changes (e.g. for online/offline hotplug memory).
In order to do this automatically, udev rules should be used. This kernel
patch adds udev events for "online" and "offline". Together with this
kernel patch, the following udev rules for online/offline have to be added
to "/etc/udev/rules.d/98-kexec.rules":
Fabio Estevam [Fri, 13 Jan 2012 01:20:20 +0000 (17:20 -0800)]
include/linux/crash_dump.h needs elf.h
Building an ARM target we get the following warnings:
CC arch/arm/kernel/setup.o
In file included from arch/arm/kernel/setup.c:39:
arch/arm/include/asm/elf.h:102:1: warning: "vmcore_elf64_check_arch" redefined
In file included from arch/arm/kernel/setup.c:24:
include/linux/crash_dump.h:30:1: warning: this is the location of the previous definition
Quoting Russell King:
"linux/crash_dump.h makes no attempt to include asm/elf.h, but it depends
on stuff in asm/elf.h to determine how stuff inside this file is defined
at parse time.
So, if asm/elf.h is included after linux/crash_dump.h or not at all, you
get a different result from the situation where asm/elf.h is included
before."
So add elf.h header to crash_dump.h to avoid this problem.
The original discussion about this can be found at:
http://www.spinics.net/lists/arm-kernel/msg154113.html
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: <stable@vger.kernel.org> [3.2.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Holzheu [Fri, 13 Jan 2012 01:20:18 +0000 (17:20 -0800)]
kdump: fix crash_kexec()/smp_send_stop() race in panic()
When two CPUs call panic at the same time there is a possible race
condition that can stop kdump. The first CPU calls crash_kexec() and the
second CPU calls smp_send_stop() in panic() before crash_kexec() finished
on the first CPU. So the second CPU stops the first CPU and therefore
kdump fails:
1st CPU:
panic()->crash_kexec()->mutex_trylock(&kexec_mutex)-> do kdump
2nd CPU:
panic()->crash_kexec()->kexec_mutex already held by 1st CPU
->smp_send_stop()-> stop 1st CPU (stop kdump)
This patch fixes the problem by introducing a spinlock in panic that
allows only one CPU to process crash_kexec() and the subsequent panic
code.
All other CPUs call the weak function panic_smp_self_stop() that stops the
CPU itself. This function can be overloaded by architecture code. For
example "tile" can use their lower-power "nap" instruction for that.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Holzheu [Fri, 13 Jan 2012 01:20:15 +0000 (17:20 -0800)]
kdump: crashk_res init check for /sys/kernel/kexec_crash_size
Currently it is possible to set the crash_size via the sysfs
/sys/kernel/kexec_crash_size even if no crash kernel memory has been
defined with the "crashkernel" parameter. In this case "crashk_res" is
not initialized and crashk_res.start = crashk_res.end = 0. Unfortunately
resource_size(&crashk_res) returns 1 in this case. This breaks the s390
implementation of crash_(un)map_reserved_pages().
To fix the problem the correct "old_size" is now calculated in
crash_shrink_memory(). "old_size is set to "0" if crashk_res is not
initialized. With this change crash_shrink_memory() will do nothing, when
"crashk_res" is not initialized. It will return "0" for "echo 0 >
/sys/kernel/kexec_crash_size" and -EINVAL for "echo [not zero] >
/sys/kernel/kexec_crash_size".
In addition to that this patch also simplifies the "ret = -EINVAL" vs.
"ret = 0" logic as suggested by Simon Horman.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Dave Young <dyoung@redhat.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Reviewed-by: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One result of this bug is that the memory chunk can never be set offline
using memory hotplug. With this patch I insert a new "System RAM"
resource for the released memory. Then the upper example looks like the
following:
WANG Cong [Fri, 13 Jan 2012 01:20:11 +0000 (17:20 -0800)]
kexec: remove KMSG_DUMP_KEXEC
KMSG_DUMP_KEXEC is useless because we already save kernel messages inside
/proc/vmcore, and it is unsafe to allow modules to do other stuffs in a
crash dump scenario.
[akpm@linux-foundation.org: fix powerpc build] Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Reported-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Jarod Wilson <jarod@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
node_to_cpumask() has been replaced by cpumask_of_node(), and wholly
removed since commit 29c337a0 ("cpumask: remove obsolete node_to_cpumask
now everyone uses cpumask_of_node").
So update the comments for setup_node_to_cpumask_map().
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kautuk Consul [Fri, 13 Jan 2012 01:20:08 +0000 (17:20 -0800)]
mm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error path
If either of the vas or vms arrays are not properly kzalloced, then the
code jumps to the err_free label.
The err_free label runs a loop to check and free each of the array members
of the vas and vms arrays which is not required for this situation as none
of the array members have been allocated till this point.
Eliminate the extra loop we have to go through by introducing a new label
err_free2 and then jumping to it.
[akpm@linux-foundation.org: remove now-unneeded tests] Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Fri, 13 Jan 2012 01:20:07 +0000 (17:20 -0800)]
mm: rearrange putback_inactive_pages
There is sometimes confusion between the global putback_lru_pages() in
migrate.c and the static putback_lru_pages() in vmscan.c: rename the
latter putback_inactive_pages(): it helps shrink_inactive_list() rather as
move_active_pages_to_lru() helps shrink_active_list().
Remove unused scan_control arg from putback_inactive_pages() and from
update_isolated_counts(). Move clear_active_flags() inside
update_isolated_counts(). Move NR_ISOLATED accounting up into
shrink_inactive_list() itself, so the balance is clearer.
Do the spin_lock_irq() before calling putback_inactive_pages() and
spin_unlock_irq() after return from it, so that it better matches
update_isolated_counts() and move_active_pages_to_lru().
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Fri, 13 Jan 2012 01:20:06 +0000 (17:20 -0800)]
mm: remove isolate_pages()
The isolate_pages() level in vmscan.c offers little but indirection: merge
it into isolate_lru_pages() as the compiler does, and use the names
nr_to_scan and nr_scanned in each case.
Hugh Dickins [Fri, 13 Jan 2012 01:20:04 +0000 (17:20 -0800)]
mm: remove del_page_from_lru, add page_off_lru
del_page_from_lru() repeats del_page_from_lru_list(), also working out
which LRU the page was on, clearing the relevant bits. Decouple those
functions: remove del_page_from_lru() and add page_off_lru().
Hugh Dickins [Fri, 13 Jan 2012 01:19:58 +0000 (17:19 -0800)]
mm: fewer underscores in ____pagevec_lru_add
What's so special about ____pagevec_lru_add() that it needs four leading
underscores? Nothing, it just helped to distinguish from
__pagevec_lru_add() in 2.6.28 development. Cut two leading underscores.
Hugh Dickins [Fri, 13 Jan 2012 01:19:56 +0000 (17:19 -0800)]
mm: take pagevecs off reclaim stack
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru()
by lists of pages_to_free: then apply Konstantin Khlebnikov's
free_hot_cold_page_list() to them instead of pagevec_release().
Which simplifies the flow (no need to drop and retake lock whenever
pagevec fills up) and reduces stale addresses in stack backtraces
(which often showed through the pagevecs); but more importantly,
removes another 120 bytes from the deepest stacks in page reclaim.
Although I've not recently seen an actual stack overflow here with
a vanilla kernel, move_active_pages_to_lru() has often featured in
deep backtraces.
However, free_hot_cold_page_list() does not handle compound pages
(nor need it: a Transparent HugePage would have been split by the
time it reaches the call in shrink_page_list()), but it is possible
for putback_lru_pages() or move_active_pages_to_lru() to be left
holding the last reference on a THP, so must exclude the unlikely
compound case before putting on pages_to_free.
Remove pagevec_strip(), its work now done in move_active_pages_to_lru().
The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c,
but that is never on the reclaim path, and cannot be replaced by a list.
Hugh Dickins [Fri, 13 Jan 2012 01:19:54 +0000 (17:19 -0800)]
memcg: fix mem_cgroup_print_bad_page
If DEBUG_VM, mem_cgroup_print_bad_page() is called whenever bad_page()
shows a "Bad page state" message, removes page from circulation, adds a
taint and continues. This is at a very low level, often when a spinlock
is held (sometimes when page table lock is held, for example).
We want to recover from this badness, not make it worse: we must not
kmalloc memory here, we must not do a cgroup path lookup via dubious
pointers. No doubt that code was useful to debug a particular case at one
time, and may be again, but take it out of the mainline kernel.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Fri, 13 Jan 2012 01:19:52 +0000 (17:19 -0800)]
memcg: fix split_huge_page_refcounts()
This patch started off as a cleanup: __split_huge_page_refcounts() has to
cope with two scenarios, when the hugepage being split is already on LRU,
and when it is not; but why does it have to split that accounting across
three different sites? Consolidate it in lru_add_page_tail(), handling
evictable and unevictable alike, and use standard add_page_to_lru_list()
when accounting is needed (when the head is not yet on LRU).
But a recent regression in -next, I guess the removal of PageCgroupAcctLRU
test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix:
under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number,
messing up reclaim calculations and causing a freeze at rmdir of cgroup.
Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap that
count - this has not been the only such incident. Document that
lru_add_page_tail() is for Transparent HugePages by #ifdef around it.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:49 +0000 (17:19 -0800)]
mm: vmscan: check if reclaim should really abort even if compaction_ready() is true for one zone
If compaction can proceed for a given zone, shrink_zones() does not
reclaim any more pages from it. After commit [e0c2327: vmscan: abort
reclaim/compaction if compaction can proceed], do_try_to_free_pages()
tries to finish as soon as possible once one zone can compact.
This was intended to prevent slabs being shrunk unnecessarily but there
are side-effects. One is that a small zone that is ready for compaction
will abort reclaim even if the chances of successfully allocating a THP
from that zone is small. It also means that reclaim can return too early
even though sc->nr_to_reclaim pages were not reclaimed.
This partially reverts the commit until it is proven that slabs are really
being shrunk unnecessarily but preserves the check to return 1 to avoid
OOM if reclaim was aborted prematurely.
[aarcange@redhat.com: This patch replaces a revert from Andrea] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:45 +0000 (17:19 -0800)]
mm: vmscan: when reclaiming for compaction, ensure there are sufficient free pages available
In commit e0887c19 ("vmscan: limit direct reclaim for higher order
allocations"), Rik noted that reclaim was too aggressive when THP was
enabled. In his initial patch he used the number of free pages to decide
if reclaim should abort for compaction. My feedback was that reclaim and
compaction should be using the same logic when deciding if reclaim should
be aborted.
Unfortunately, this had the effect of reducing THP success rates when the
workload included something like streaming reads that continually
allocated pages. The window during which compaction could run and return
a THP was too small.
This patch combines Rik's two patches together. compaction_suitable() is
still used to decide if reclaim should be aborted to allow compaction is
used. However, it will also ensure that there is a reasonable buffer of
free pages available. This improves upon the THP allocation success rates
but bounds the number of pages that are freed for compaction.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:43 +0000 (17:19 -0800)]
mm: compaction: introduce sync-light migration for use by compaction
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage. Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.
This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.
[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:41 +0000 (17:19 -0800)]
mm: page allocator: do not call direct reclaim for THP allocations while compaction is deferred
If compaction is deferred, direct reclaim is used to try to free enough
pages for the allocation to succeed. For small high-orders, this has a
reasonable chance of success. However, if the caller has specified
__GFP_NO_KSWAPD to limit the disruption to the system, it makes more sense
to fail the allocation rather than stall the caller in direct reclaim.
This patch skips direct reclaim if compaction is deferred and the caller
specifies __GFP_NO_KSWAPD.
Async compaction only considers a subset of pages so it is possible for
compaction to be deferred prematurely and not enter direct reclaim even in
cases where it should. To compensate for this, this patch also defers
compaction only if sync compaction failed.
Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:38 +0000 (17:19 -0800)]
mm: compaction: make isolate_lru_page() filter-aware again
Commit 39deaf85 ("mm: compaction: make isolate_lru_page() filter-aware")
noted that compaction does not migrate dirty or writeback pages and that
is was meaningless to pick the page and re-add it to the LRU list. This
had to be partially reverted because some dirty pages can be migrated by
compaction without blocking.
This patch updates "mm: compaction: make isolate_lru_page" by skipping
over pages that migration has no possibility of migrating to minimise LRU
disruption.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:34 +0000 (17:19 -0800)]
mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage
Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time. Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates. Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;
This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking. This
patch updates the ->migratepage callback with a "sync" parameter. It is
the responsibility of the callback to fail gracefully if migration would
block.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:33 +0000 (17:19 -0800)]
mm: vmscan: do not OOM if aborting reclaim to start compaction
During direct reclaim it is possible that reclaim will be aborted so that
compaction can be attempted to satisfy a high-order allocation. If this
decision is made before any pages are reclaimed, it is possible that 0 is
returned to the page allocator potentially triggering an OOM. This has
not been observed but it is a possibility so this patch addresses it.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrea Arcangeli [Fri, 13 Jan 2012 01:19:29 +0000 (17:19 -0800)]
mm: vmscan: check if we isolated a compound page during lumpy scan
Properly take into account if we isolated a compound page during the lumpy
scan in reclaim and skip over the tail pages when encountered. This
corrects the values given to the tracepoint for number of lumpy pages
isolated and will avoid breaking the loop early if compound pages smaller
than the requested allocation size are requested.
[mgorman@suse.de: Updated changelog] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:26 +0000 (17:19 -0800)]
mm: compaction: use synchronous compaction for /proc/sys/vm/compact_memory
When asynchronous compaction was introduced, the
/proc/sys/vm/compact_memory handler should have been updated to always use
synchronous compaction. This did not happen so this patch addresses it.
The assumption is if a user writes to /proc/sys/vm/compact_memory, they
are willing for that process to stall.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 13 Jan 2012 01:19:22 +0000 (17:19 -0800)]
mm: compaction: allow compaction to isolate dirty pages
Short summary: There are severe stalls when a USB stick using VFAT is
used with THP enabled that are reduced by this series. If you are
experiencing this problem, please test and report back and considering I
have seen complaints from openSUSE and Fedora users on this as well as a
few private mails, I'm guessing it's a widespread issue. This is a new
type of USB-related stall because it is due to synchronous compaction
writing where as in the past the big problem was dirty pages reaching
the end of the LRU and being written by reclaim.
Am cc'ing Andrew this time and this series would replace
mm-do-not-stall-in-synchronous-compaction-for-thp-allocations.patch.
I'm also cc'ing Dave Jones as he might have merged that patch to Fedora
for wider testing and ideally it would be reverted and replaced by this
series.
That said, the later patches could really do with some review. If this
series is not the answer then a new direction needs to be discussed
because as it is, the stalls are unacceptable as the results in this
leader show.
For testers that try backporting this to 3.1, it won't work because
there is a non-obvious dependency on not writing back pages in direct
reclaim so you need those patches too.
Changelog since V5
o Rebase to 3.2-rc5
o Tidy up the changelogs a bit
Changelog since V4
o Added reviewed-bys, credited Andrea properly for sync-light
o Allow dirty pages without mappings to be considered for migration
o Bound the number of pages freed for compaction
o Isolate PageReclaim pages on their own LRU list
This is against 3.2-rc5 and follows on from discussions on "mm: Do
not stall in synchronous compaction for THP allocations" and "[RFC
PATCH 0/5] Reduce compaction-related stalls". Initially, the proposed
patch eliminated stalls due to compaction which sometimes resulted in
user-visible interactivity problems on browsers by simply never using
sync compaction. The downside was that THP success allocation rates
were lower because dirty pages were not being migrated as reported by
Andrea. His approach at fixing this was nacked on the grounds that
it reverted fixes from Rik merged that reduced the amount of pages
reclaimed as it severely impacted his workloads performance.
This series attempts to reconcile the requirements of maximising THP
usage, without stalling in a user-visible fashion due to compaction
or cheating by reclaiming an excessive number of pages.
Patch 1 partially reverts commit 39deaf85 to allow migration to isolate
dirty pages. This is because migration can move some dirty
pages without blocking.
Patch 2 notes that the /proc/sys/vm/compact_memory handler is not using
synchronous compaction when it should be. This is unrelated
to the reported stalls but is worth fixing.
Patch 3 checks if we isolated a compound page during lumpy scan and
account for it properly. For the most part, this affects
tracing so it's unrelated to the stalls but worth fixing.
Patch 4 notes that it is possible to abort reclaim early for compaction
and return 0 to the page allocator potentially entering the
"may oom" path. This has not been observed in practice but
the rest of the series potentially makes it easier to happen.
Patch 5 adds a sync parameter to the migratepage callback and gives
the callback responsibility for migrating the page without
blocking if sync==false. For example, fallback_migrate_page
will not call writepage if sync==false. This increases the
number of pages that can be handled by asynchronous compaction
thereby reducing stalls.
Patch 6 restores filter-awareness to isolate_lru_page for migration.
In practice, it means that pages under writeback and pages
without a ->migratepage callback will not be isolated
for migration.
Patch 7 avoids calling direct reclaim if compaction is deferred but
makes sure that compaction is only deferred if sync
compaction was used.
Patch 8 introduces a sync-light migration mechanism that sync compaction
uses. The objective is to allow some stalls but to not call
->writepage which can lead to significant user-visible stalls.
Patch 9 notes that while we want to abort reclaim ASAP to allow
compation to go ahead that we leave a very small window of
opportunity for compaction to run. This patch allows more pages
to be freed by reclaim but bounds the number to a reasonable
level based on the high watermark on each zone.
Patch 10 allows slabs to be shrunk even after compaction_ready() is
true for one zone. This is to avoid a problem whereby a single
small zone can abort reclaim even though no pages have been
reclaimed and no suitably large zone is in a usable state.
Patch 11 fixes a problem with the rate of page scanning. As reclaim is
rarely stalling on pages under writeback it means that scan
rates are very high. This is particularly true for direct
reclaim which is not calling writepage. The vmstat figures
implied that much of this was busy work with PageReclaim pages
marked for immediate reclaim. This patch is a prototype that
moves these pages to their own LRU list.
This has been tested and other than 2 USB keys getting trashed,
nothing horrible fell out. That said, I am a bit unhappy with the
rescue logic in patch 11 but did not find a better way around it. It
does significantly reduce scan rates and System CPU time indicating
it is the right direction to take.
What is of critical importance is that stalls due to compaction
are massively reduced even though sync compaction was still
allowed. Testing from people complaining about stalls copying to USBs
with THP enabled are particularly welcome.
The following tests all involve THP usage and USB keys in some
way. Each test follows this type of pattern
1. Read from some fast fast storage, be it raw device or file. Each time
the copy finishes, start again until the test ends
2. Write a large file to a filesystem on a USB stick. Each time the copy
finishes, start again until the test ends
3. When memory is low, start an alloc process that creates a mapping
the size of physical memory to stress THP allocation. This is the
"real" part of the test and the part that is meant to trigger
stalls when THP is enabled. Copying continues in the background.
4. Record the CPU usage and time to execute of the alloc process
5. Record the number of THP allocs and fallbacks as well as the number of THP
pages in use a the end of the test just before alloc exited
6. Run the test 5 times to get an idea of variability
7. Between each run, sync is run and caches dropped and the test
waits until nr_dirty is a small number to avoid interference
or caching between iterations that would skew the figures.
The individual tests were then
writebackCPDeviceBasevfat
Disable THP, read from a raw device (sda), vfat on USB stick
writebackCPDeviceBaseext4
Disable THP, read from a raw device (sda), ext4 on USB stick
writebackCPDevicevfat
THP enabled, read from a raw device (sda), vfat on USB stick
writebackCPDeviceext4
THP enabled, read from a raw device (sda), ext4 on USB stick
writebackCPFilevfat
THP enabled, read from a file on fast storage and USB, both vfat
writebackCPFileext4
THP enabled, read from a file on fast storage and USB, both ext4
The kernels tested were
3.1 3.1
vanilla 3.2-rc5
freemore Patches 1-10
immediate Patches 1-11
andrea The 8 patches Andrea posted as a basis of comparison
The results are very long unfortunately. I'll start with the case
where we are not using THP at all
The THP figures are obviously all 0 because THP was enabled. The
main thing to watch is the elapsed times and how they compare to
times when THP is enabled later. It's also important to note that
elapsed time is improved by this series as System CPu time is much
reduced.
The first thing to note is the "Elapsed Time" for the vanilla kernels
of 2249 seconds versus 56 with THP disabled which might explain the
reports of USB stalls with THP enabled. Applying the patches brings
performance in line with THP-disabled performance while isolating
pages for immediate reclaim from the LRU cuts down System CPU time.
The "Fault Alloc" success rate figures are also improved. The vanilla
kernel only managed to allocate 76.6 pages on average over the course
of 5 iterations where as applying the series allocated 181.20 on
average albeit it is well within variance. It's worth noting that
applies the series at least descreases the amount of variance which
implies an improvement.
Andrea's series had a higher success rate for THP allocations but
at a severe cost to elapsed time which is still better than vanilla
but still much worse than disabling THP altogether. One can bring my
series close to Andrea's by removing this check
/*
* If compaction is deferred for high-order allocations, it is because
* sync compaction recently failed. In this is the case and the caller
* has requested the system not be heavily disrupted, fail the
* allocation now instead of entering direct reclaim
*/
if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
goto nopage;
I didn't include a patch that removed the above check because hurting
overall performance to improve the THP figure is not what the average
user wants. It's something to consider though if someone really wants
to maximise THP usage no matter what it does to the workload initially.
This is summary of vmstat figures from the same test.
1. Page In/out figures are much reduced by the series.
2. Direct page scanning is incredibly high (264745.137 pages scanned
per second on the vanilla kernel) but isolating PageReclaim pages
on their own list reduces the number of pages scanned significantly.
3. The fact that "Page rescued immediate" is a positive number implies
that we sometimes race removing pages from the LRU_IMMEDIATE list
that need to be put back on a normal LRU but it happens only for
0.07% of the pages marked for immediate reclaim.
Similar test but the USB stick is using ext4 instead of vfat. As
ext4 does not use writepage for migration, the large stalls due to
compaction when THP is enabled are not observed. Still, isolating
PageReclaim pages on their own list helped completion time largely
by reducing the number of pages scanned by direct reclaim although
time spend in congestion_wait could also be a factor.
Again, Andrea's series had far higher success rates for THP allocation
at the cost of elapsed time. I didn't look too closely but a quick
look at the vmstat figures tells me kswapd reclaimed 8 times more pages
than the patch series and direct reclaim reclaimed roughly three times
as many pages. It follows that if memory is aggressively reclaimed,
there will be more available for THP.
In this case, the test is reading/writing only from filesystems but as
it's vfat, it's slow due to calling writepage during compaction. Little
to observe really - the time to complete the test goes way down
with the series applied and THP allocation success rates go up in
comparison to 3.2-rc5. The success rates are lower than 3.1.0 but
the elapsed time for that kernel is abysmal so it is not really a
sensible comparison.
As before, Andrea's series allocates more THPs at the cost of overall
performance.
Same type of story - elapsed times go down. In this case, allocation
success rates are roughtly the same. As before, Andrea's has higher
success rates but takes a lot longer.
Overall the series does reduce latencies and while the tests are
inherency racy as alloc competes with the cp processes, the variability
was included. The THP allocation rates are not as high as they could
be but that is because we would have to be more aggressive about
reclaim and compaction impacting overall performance.
This patch:
Commit 39deaf85 ("mm: compaction: make isolate_lru_page() filter-aware")
noted that compaction does not migrate dirty or writeback pages and that
is was meaningless to pick the page and re-add it to the LRU list.
What was missed during review is that asynchronous migration moves dirty
pages if their ->migratepage callback is migrate_page() because these can
be moved without blocking. This potentially impacted hugepage allocation
success rates by a factor depending on how many dirty pages are in the
system.
This patch partially reverts 39deaf85 to allow migration to isolate dirty
pages again. This increases how much compaction disrupts the LRU but that
is addressed later in the series.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tao Ma [Fri, 13 Jan 2012 01:19:20 +0000 (17:19 -0800)]
vmscan/trace: Add 'file' info to trace_mm_vmscan_lru_isolate()
In trace_mm_vmscan_lru_isolate(), we don't output 'file' information to
the trace event and it is a bit inconvenient for the user to get the
real information(like pasted below). mm_vmscan_lru_isolate:
isolate_mode=2 order=0 nr_requested=32 nr_scanned=32 nr_taken=32
contig_taken=0 contig_dirty=0 contig_failed=0
'active' can be obtained by analyzing mode(Thanks go to Minchan and
Mel), So this patch adds 'file' to the trace event and it now looks
like: mm_vmscan_lru_isolate: isolate_mode=2 order=0 nr_requested=32
nr_scanned=32 nr_taken=32 contig_taken=0 contig_dirty=0 contig_failed=0
file=0
Signed-off-by: Tao Ma <boyu.mt@taobao.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>