Chanho Min [Mon, 8 Jul 2013 23:01:49 +0000 (16:01 -0700)]
lib: add lz4 compressor module
This patchset is for supporting LZ4 compression and the crypto API using
it.
As shown below, the size of data is a little bit bigger but compressing
speed is faster under the enabled unaligned memory access. We can use
lz4 de/compression through crypto API as well. Also, It will be useful
for another potential user of lz4 compression.
lz4 Compression Benchmark:
Compiler: ARM gcc 4.6.4
ARMv7, 1 GHz based board
Kernel: linux 3.4
Uncompressed data Size: 101 MB
Compressed Size compression Speed
LZO 72.1MB 32.1MB/s, 33.0MB/s(UA)
LZ4 75.1MB 30.4MB/s, 35.9MB/s(UA)
LZ4HC 59.8MB 2.4MB/s, 2.5MB/s(UA)
- UA: Unaligned memory Access support
- Latest patch set for LZO applied
This patch:
Add support for LZ4 compression in the Linux Kernel. LZ4 Compression APIs
for kernel are based on LZ4 implementation by Yann Collet and were changed
for kernel coding style.
lz4_compress() support basic lz4 compression whereas lz4hc_compress()
support high compression or CPU performance get lower but compression
ratio get higher. Also, we require the pre-allocated working memory with
the defined size and destination buffer must be allocated with the size of
lz4_compressbound.
[akpm@linux-foundation.org: make lz4_compresshcctx() static] Signed-off-by: Chanho Min <chanho.min@lge.com> Cc: "Darrick J. Wong" <djwong@us.ibm.com> Cc: Bob Pearson <rpearson@systemfabricworks.com> Cc: Richard Weinberger <richard@nod.at> Cc: Herbert Xu <herbert@gondor.hengli.com.au> Cc: Yann Collet <yann.collet.73@gmail.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2. ARMv7, 1.7GHz based board
Kernel: linux 3.7
Uncompressed Kernel Size: 14MB
Compressed Size Decompression Speed
LZO 6.0MB 34.1MB/s, 52.2MB/s(UA)
LZ4 6.5MB 86.7MB/s
- UA: Unaligned memory Access support
- Latest patch set for LZO applied
This patch set is for adding support for LZ4-compressed Kernel. LZ4 is a
very fast lossless compression algorithm and it also features an extremely
fast decoder [1].
But we have five of decompressors already and one question which does
arise, however, is that of where do we stop adding new ones? This issue
had been discussed and came to the conclusion [2].
Russell King said that we should have:
- one decompressor which is the fastest
- one decompressor for the highest compression ratio
- one popular decompressor (eg conventional gzip)
If we have a replacement one for one of these, then it should do exactly
that: replace it.
The benchmark shows that an 8% increase in image size vs a 66% increase
in decompression speed compared to LZO(which has been known as the
fastest decompressor in the Kernel). Therefore the "fast but may not be
small" compression title has clearly been taken by LZ4 [3].
Chanho Min [Mon, 8 Jul 2013 23:01:43 +0000 (16:01 -0700)]
lib: add weak clz/ctz functions
Some architectures need __c[lt]z[sd]i2() for __builtin_c[lt]z[ll] and
that causes a build failure. They can be implemented using the
fls()/__ffs() and overridden by linking arch-specific versions may not
be implemented yet.
This is required by "lib: add lz4 compressor module".
Reference: https://lkml.org/lkml/2013/4/18/603
Signed-off-by: Chanho Min <chanho.min@lge.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "Darrick J. Wong" <djwong@us.ibm.com> Cc: Bob Pearson <rpearson@systemfabricworks.com> Cc: Richard Weinberger <richard@nod.at> Cc: Herbert Xu <herbert@gondor.hengli.com.au> Cc: Yann Collet <yann.collet.73@gmail.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:42 +0000 (16:01 -0700)]
reboot: move arch/x86 reboot= handling to generic kernel
Merge together the unicore32, arm, and x86 reboot= command line
parameter handling.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:40 +0000 (16:01 -0700)]
reboot: arm: change reboot_mode to use enum reboot_mode
Preparing to move the parsing of reboot= to generic kernel code forces
the change in reboot_mode handling to use the enum.
[akpm@linux-foundation.org: fix arch/arm/mach-socfpga/socfpga.c] Signed-off-by: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:39 +0000 (16:01 -0700)]
reboot: arm: prepare reboot_mode for moving to generic kernel code
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:38 +0000 (16:01 -0700)]
reboot: arm: remove unused restart_mode fields from some arm subarchs
These restart_mode fields are not used at all. Remove them to make
moving the reboot= cmdline options to the general kernel easier.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:36 +0000 (16:01 -0700)]
reboot: unicore32: prepare reboot_mode for moving to generic kernel code
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:35 +0000 (16:01 -0700)]
reboot: x86: prepare reboot_mode for moving to generic kernel code
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Miguel Boton <mboton.lkml@gmail.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:34 +0000 (16:01 -0700)]
reboot: checkpatch.pl the new kernel/reboot.c file
Get the new file to pass scripts/checkpatch.pl
Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Robin Holt [Mon, 8 Jul 2013 23:01:32 +0000 (16:01 -0700)]
reboot: move shutdown/reboot related functions to kernel/reboot.c
This patch is preparatory. It moves reboot related syscall, etc
functions from kernel/sys.c to kernel/reboot.c.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the prior patch's #define for easier backporting to the stable
releases.
Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
partitions/msdos: enumerate also AIX LVM partitions
Graft AIX partitions enumeration into partitions/msdos.c
There is already a AIX disks detection logic in msdos.c. When an AIX disk
has been found, and if configured to, call the aix partitions recognizer.
This avoids removal of AIX disks protection from msdos.c, avoids code
duplication, and ensures that AIX partitions enumeration is called before
plain msdos partitions enumeration.
Signed-off-by: Philippe De Muyter <phdm@macqel.be> Cc: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
AIX LVM permits to make "logical volumes" which are made of multiple
slices of multiple disks. The new code allows only access to the
"logical volumes" which are made of one slice on the probed disk, a
slice being a contiguous disk area. The code also detects "logical
volumes" made of multiple slices on the probed disk, but can not
describe them to the partition layer, because the partition layer
generic code does not support that. When such non-contiguous "logical
volumes" are detected, a diagnostic message is printed.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Philippe De Muyter <phdm@macqel.be> Cc: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Carpenter [Mon, 8 Jul 2013 23:01:27 +0000 (16:01 -0700)]
mwave: fix info leak in mwave_ioctl()
Smatch complains that on 64 bit systems, there is a hole in the
MW_ABILITIES struct between ->component_count and ->component_list[].
It leaks stack information from the mwave_ioctl() function.
I've added a memset() to initialize the struct to zero.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Greg KH <greg@kroah.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ipc/sem.c: replace shared sem_otime with per-semaphore value
sem_otime contains the time of the last semaphore operation that
completed successfully. Every operation updates this value, thus access
from multiple cpus can cause thrashing.
Therefore the patch replaces the variable with a per-semaphore variable.
The per-array sem_otime is only calculated when required.
No performance improvement on a single-socket i3 - only important for
larger systems.
ipc/sem.c: always use only one queue for alter operations
There are two places that can contain alter operations:
- the global queue: sma->pending_alter
- the per-semaphore queues: sma->sem_base[].pending_alter.
Since one of the queues must be processed first, this causes an odd
priorization of the wakeups: complex operations have priority over
simple ops.
The patch restores the behavior of linux <=3.0.9: The longest waiting
operation has the highest priority.
This is done by using only one queue:
- if there are complex ops, then sma->pending_alter is used.
- otherwise, the per-semaphore queues are used.
As a side effect, do_smart_update_queue() becomes much simpler: no more
goto logic.
ipc/sem: separate wait-for-zero and alter tasks into seperate queues
Introduce separate queues for operations that do not modify the
semaphore values. Advantages:
- Simpler logic in check_restart().
- Faster update_queue(): Right now, all wait-for-zero operations are
always tested, even if the semaphore value is not 0.
- wait-for-zero gets again priority, as in linux <=3.0.9
i3, with 2 cores and with hyperthreading enabled. Interleave 2 in order
use first the full cores. HT partially hides the delay from cacheline
trashing, thus the improvement is "only" 8.7% if 4 threads are running.
Enforce that ipc_rcu_alloc returns a cacheline aligned pointer on SMP.
Rationale:
The SysV sem code tries to move the main spinlock into a seperate
cacheline (____cacheline_aligned_in_smp). This works only if
ipc_rcu_alloc returns cacheline aligned pointers. vmalloc and kmalloc
return cacheline algined pointers, the implementation of ipc_rcu_alloc
breaks that.
While the INFO cmd doesn't take the ipc lock, the STAT commands do
acquire it unnecessarily. We can do the permissions and security checks
only holding the rcu lock.
ipc,msg: introduce lockless functions to obtain the ipc object
Add msq_obtain_object() and msq_obtain_object_check(), which will allow
us to get the ipc object without acquiring the lock. Just as with
semaphores, these functions are basically wrappers around
ipc_obtain_object*().
Similar to semctl, when calling msgctl, the *_INFO and *_STAT commands
can be performed without acquiring the ipc object.
Add a msgctl_nolock() function and move the logic of *_INFO and *_STAT
out of msgctl(). This change still takes the lock and it will be
properly lockless in the next patch
This function currently acquires both the rw_mutex and the rcu lock on
successful lookups, leaving the callers to explicitly unlock them,
creating another two level locking situation.
Make the callers (including those that still use ipcctl_pre_down())
explicitly lock and unlock the rwsem and rcu lock.
This patchset continues the work that began in the sysv ipc semaphore
scaling series, see
https://lkml.org/lkml/2013/3/20/546
Just like semaphores used to be, sysv shared memory and msg queues also
abuse the ipc lock, unnecessarily holding it for operations such as
permission and security checks.
This patchset mostly deals with mqueues, and while shared mem can be
done in a very similar way, I want to get these patches out in the open
first. It also does some pending cleanups, mostly focused on the two
level locking we have in ipc code, taking care of ipc_addid() and
ipcctl_pre_down_nolock() - yes there are still functions that need to be
updated as well.
This patch:
Make all callers explicitly take and release the RCU read lock.
This addresses the two level locking seen in newary(), newseg() and
newqueue(). For the last two, explicitly unlock the ipc object and the
rcu lock, instead of calling the custom shm_unlock and msg_unlock
functions. The next patch will deal with the open coded locking for
->perm.lock
ptrace/x86: flush_ptrace_hw_breakpoint() shoule clear the virtual debug registers
flush_ptrace_hw_breakpoint() destroys the counters set by ptrace, but
"leaks" ->debugreg6 and ->ptrace_dr7.
The problem is minor, but still it doesn't look right and flush_thread()
did this until commit 66cb59172959 ("hw-breakpoints: use the new wrapper
routines to access debug registers in process/thread code"). Now that
PTRACE_DETACH does flush_ too this makes even more sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child)
Change ptrace_detach() to call flush_ptrace_hw_breakpoint(child). This
frees the slots for non-ptrace PERF_TYPE_BREAKPOINT users, and this
ensures that the tracee won't be killed by SIGTRAP triggered by the
active breakpoints.
Test-case:
unsigned long encode_dr7(int drnum, int enable, unsigned int type, unsigned int len)
{
unsigned long dr7;
ptrace/x86: dont delay "disable" till second pass in ptrace_write_dr7()
ptrace_write_dr7() skips ptrace_modify_breakpoint(disabled => true)
unless second_pass, this buys nothing but complicates the code and means
that we always do the main loop twice even if "disabled" was never true.
The comment says:
Don't unregister the breakpoints right-away,
unless all register_user_hw_breakpoint()
requests have succeeded.
Firstly, we do not do register_user_hw_breakpoint(), it was removed by
commit 24f1e32c60c4 ("hw-breakpoints: Rewrite the hw-breakpoints layer
on top of perf events").
We are going to restore register_user_hw_breakpoint() (see the next
patch) but this doesn't matter: after commit 44234adcdce3
("hw-breakpoints: Modify breakpoints without unregistering them")
perf_event_disable() can not hurt, hw_breakpoint_del() does not free the
slot.
Remove the "second_pass" check from the main loop and simplify the code.
Since we have to check "bp != NULL" anyway, the patch also removes the
same check in ptrace_modify_breakpoint() and moves the comment into
ptrace_write_dr7().
With this patch the second pass is only needed to restore the saved
old_dr7. This should never fail, so the patch adds WARN_ON() to catch
the potential problems as Frederic suggested.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/x86: simplify the "disable" logic in ptrace_write_dr7()
ptrace_write_dr7() looks unnecessarily overcomplicated. We can factor
out ptrace_modify_breakpoint() and do not do "continue" twice, just we
need to pass the proper "disabled" argument to
ptrace_modify_breakpoint().
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace: revert "Prepare to fix racy accesses on task breakpoints"
This reverts commit bf26c018490c ("Prepare to fix racy accesses on task
breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Now that ptrace_get_breakpoints/ptrace_put_breakpoints have no callers,
we can kill them and remove task->ptrace_bp_refcnt.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Michael Neuling <mikey@neuling.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/sh: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit e0ac8457d020 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/arm: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit bf0b8f4b55e5 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/powerpc: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit 07fa7a0a8a58 ("hw_breakpoints: Fix racy access to
ptrace breakpoints") and removes ptrace_get/put_breakpoints() added by
other commits.
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michael Neuling <mikey@neuling.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/x86: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit 87dc669ba257 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
The patch only removes ptrace_get_breakpoints/ptrace_put_breakpoints and
does a couple of "while at it" cleanups, it doesn't remove other changes
from the reverted commit.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Lockwood [Mon, 8 Jul 2013 23:00:46 +0000 (16:00 -0700)]
fatfs: add FAT_IOCTL_GET_VOLUME_ID
This patch, originally from Android kernel, adds vfat ioctl command
FAT_IOCTL_GET_VOLUME_ID, with this command we can get the vfat volume ID
using following code:
ioctl(fd, FAT_IOCTL_GET_VOLUME_ID, &volume_ID)
This patch is a modified version of the patch by Mike Lockwood, with
changes from Dmitry Pervushin, who noticed the original patch makes some
volume IDs abiguous with error returns: for example, if volume id is
0xFFFFFDAD, that matches -ENOIOCTLCMD, we get "FFFFFFFF" from the user
space.
So add a parameter to ioctl to get the correct volume ID.
Android uses vfat volume ID to identify different sd card, when a new sd
card is inserted to device, android can scan the media on it and pop up
new contents.
Signed-off-by: Bintian Wang <bintian.wang@linaro.org> Cc: dmitry pervushin <dpervushin@gmail.com> Cc: Mike Lockwood <lockwood@android.com> Cc: Colin Cross <ccross@android.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: John Stultz <john.stultz@linaro.org> Cc: Sean McNeil <sean@mcneil.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memory_hotplug.c: fix return value of online_pages()
online_pages() is called from memory_block_action() when a user requests
to online a memory block via sysfs. This function needs to return a
proper error value in case of error.
Michal Hocko [Mon, 8 Jul 2013 23:00:40 +0000 (16:00 -0700)]
mm: honor min_free_kbytes set by user
min_free_kbytes is updated during memory hotplug (by
init_per_zone_wmark_min) currently which is right thing to do in most
cases but this could be unexpected if admin increased the value to
prevent from allocation failures and the new min_free_kbytes would be
decreased as a result of memory hotadd.
This patch saves the user defined value and allows updating
min_free_kbytes only if it is higher than the saved one.
A warning is printed when the new value is ignored.
Li Zefan [Mon, 8 Jul 2013 23:00:38 +0000 (16:00 -0700)]
memcg: don't need to free memcg via RCU or workqueue
Now memcg has the same life cycle with its corresponding cgroup, and a
cgroup is freed via RCU and then mem_cgroup_css_free() will be called in
a work function, so we can simply call __mem_cgroup_free() in
mem_cgroup_css_free().
This actually reverts commit 59927fb984d ("memcg: free mem_cgroup by RCU
to fix oops").
Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:34 +0000 (16:00 -0700)]
memcg: use css_get/put for swap memcg
Use css_get/put instead of mem_cgroup_get/put. A simple replacement
will do.
The historical reason that memcg has its own refcnt instead of always
using css_get/put, is that cgroup couldn't be removed if there're still
css refs, so css refs can't be used as long-lived reference. The
situation has changed so that rmdir a cgroup will succeed regardless css
refs, but won't be freed until css refs goes down to 0.
Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:33 +0000 (16:00 -0700)]
memcg: use css_get/put when charging/uncharging kmem
Use css_get/put instead of mem_cgroup_get/put.
We can't do a simple replacement, because here mem_cgroup_put() is
called during mem_cgroup_css_free(), while mem_cgroup_css_free() won't
be called until css refcnt goes down to 0.
Instead we increment css refcnt in mem_cgroup_css_offline(), and then
check if there's still kmem charges. If not, css refcnt will be
decremented immediately, otherwise the refcnt will be released after the
last kmem allocation is uncahred.
[akpm@linux-foundation.org: tweak comment] Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:31 +0000 (16:00 -0700)]
memcg: don't use mem_cgroup_get() when creating a kmemcg cache
Use css_get()/css_put() instead of mem_cgroup_get()/mem_cgroup_put().
There are two things being done in the current code:
First, we acquired a css_ref to make sure that the underlying cgroup
would not go away. That is a short lived reference, and it is put as
soon as the cache is created.
At this point, we acquire a long-lived per-cache memcg reference count
to guarantee that the memcg will still be alive.
Li Zefan [Mon, 8 Jul 2013 23:00:30 +0000 (16:00 -0700)]
memcg: use css_get() in sock_update_memcg()
Use css_get/css_put instead of mem_cgroup_get/put.
Note, if at the same time someone is moving @current to a different
cgroup and removing the old cgroup, css_tryget() may return false, and
sock->sk_cgrp won't be initialized, which is fine.
Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Mon, 8 Jul 2013 23:00:29 +0000 (16:00 -0700)]
memcg, kmem: fix reference count handling on the error path
mem_cgroup_css_online calls mem_cgroup_put if memcg_init_kmem fails.
This is not correct because only memcg_propagate_kmem takes an
additional reference while mem_cgroup_sockets_init is allowed to fail as
well (although no current implementation fails) but it doesn't take any
reference. This all suggests that it should be memcg_propagate_kmem
that should clean up after itself so this patch moves mem_cgroup_put
over there.
Unfortunately this is not that easy (as pointed out by Li Zefan) because
memcg_kmem_mark_dead marks the group dead (KMEM_ACCOUNTED_DEAD) if it is
marked active (KMEM_ACCOUNTED_ACTIVE) which is the case even if
memcg_propagate_kmem fails so the additional reference is dropped in
that case in kmem_cgroup_destroy which means that the reference would be
dropped two times.
The easiest way then would be to simply remove mem_cgrroup_put from
mem_cgroup_css_online and rely on kmem_cgroup_destroy doing the right
thing.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.8] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_put is hierarchy aware so mem_cgroup_put(memcg) already drops
an additional reference from all parents so the additional
mem_cgrroup_put(parent) potentially causes use-after-free.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jörn Engel [Mon, 8 Jul 2013 23:00:26 +0000 (16:00 -0700)]
mmap: allow MAP_HUGETLB for hugetlbfs files v2
It is counterintuitive at best that mmap'ing a hugetlbfs file with
MAP_HUGETLB fails, while mmap'ing it without will a) succeed and b)
return huge pages.
v2: use is_file_hugepages(), as suggested by Jianguo
mm: vmscan: do not scale writeback pages when deciding whether to set ZONE_WRITEBACK
After the patch "mm: vmscan: Flatten kswapd priority loop" was merged
the scanning priority of kswapd changed.
The priority now rises until it is scanning enough pages to meet the
high watermark. shrink_inactive_list sets ZONE_WRITEBACK if a number of
pages were encountered under writeback but this value is scaled based on
the priority. As kswapd frequently scans with a higher priority now it
is relatively easy to set ZONE_WRITEBACK. This patch removes the
scaling and treates writeback pages similar to how it treats unqueued
dirty pages and congested pages. The user-visible effect should be that
kswapd will writeback fewer pages from reclaim context.
Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: vmscan: do not continue scanning if reclaim was aborted for compaction
Direct reclaim is not aborting to allow compaction to go ahead properly.
do_try_to_free_pages is told to abort reclaim which is happily ignores
and instead increases priority instead until it reaches 0 and starts
shrinking file/anon equally. This patch corrects the situation by
aborting reclaim when requested instead of raising priority.
Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: fix an overflow bug in alloc_vmap_area()
When searching a vmap area in the vmalloc space, we use (addr + size -
1) to check if the value is less than addr, which is an overflow. But
we assign (addr + size) to vmap_area->va_end.
Wanpeng Li [Mon, 8 Jul 2013 23:00:17 +0000 (16:00 -0700)]
mm/pgtable: don't accumulate addr during pgd prepopulate pmd
The old codes accumulate addr to get right pmd, however, currently pmds
are preallocated and transfered as a parameter, there is unnecessary to
accumulate addr variable any more, this patch remove it.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:16 +0000 (16:00 -0700)]
mm/page_alloc: fix doc for numa_zonelist_order
The default zonelist order selecter will select "node" order if any nodes
DMA zone comprises greater than 70% of its local memory instead of 60%,
according to default_zonelist_order::low_kmem_size > total * 70/100.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:15 +0000 (16:00 -0700)]
mm/writeback: commit reason of WB_REASON_FORKER_THREAD mismatch name
After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue"), there is no bdi forker thread
any more. However, WB_REASON_FORKER_THREAD is still used due to it is
TPs userland visible and we won't be exposing exactly the same
information with just a different name.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:14 +0000 (16:00 -0700)]
mm/writeback: don't check force_wait to handle bdi->work_list
After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue"), bdi_writeback_workfn runs off
bdi_writeback->dwork, on each execution, it processes bdi->work_list and
reschedules if there are more things to do instead of flush any work
that race with us existing. It is unecessary to check force_wait in
wb_do_writeback since it is always 0 after the mentioned commit. This
patch remove the force_wait in wb_do_writeback.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Haicheng Li [Mon, 8 Jul 2013 23:00:11 +0000 (16:00 -0700)]
fs/fs-writeback.c: : make wb_do_writeback() as static
It's not used globally and could be static.
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/sparse.c: put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE
With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:
mm/sparse.c:755: warning: `clear_hwpoisoned_pages' defined but not used
And Bisecting it ended up pointing to 4edd7ceff ("mm, hotplug: avoid
compiling memory hotremove functions when disabled").
This is because the commit above put sparse_remove_one_section() within
the protection of CONFIG_MEMORY_HOTREMOVE but the only user of
clear_hwpoisoned_pages() is sparse_remove_one_section(), and it is not
within the protection of CONFIG_MEMORY_HOTREMOVE.
So put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE should fix
the warning.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vfree: don't schedule free_work() if llist_add() returns false
vfree() only needs schedule_work(&p->wq) if p->list was empty, otherwise
vfree_deferred->wq is already pending or it is running and didn't do
llist_del_all() yet.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> 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>
mm/page_alloc.c: remove unlikely() from the current_order test
In __rmqueue_fallback(), current_order loops down from MAX_ORDER - 1 to
the order passed. MAX_ORDER is typically 11 and pageblock_order is
typically 9 on x86. Integer division truncates, so pageblock_order / 2
is 4. For the first eight iterations, it's guaranteed that
current_order >= pageblock_order / 2 if it even gets that far!
So just remove the unlikely(), it's completely bogus.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Suggested-by: David Rientjes <rientjes@google.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>
mm/page_alloc.c: remove zone_type argument of build_zonelists_node
The callers of build_zonelists_node always pass MAX_NR_ZONES -1 as the
zone_type argument, so we can directly use the value in
build_zonelists_node and remove zone_type argument.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.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>
Glauber Costa [Mon, 8 Jul 2013 23:00:01 +0000 (16:00 -0700)]
memcg: do not account memory used for cache creation
The memory we used to hold the memcg arrays is currently accounted to
the current memcg. But that creates a problem, because that memory can
only be freed after the last user is gone. Our only way to know which
is the last user, is to hook up to freeing time, but the fact that we
still have some in flight kmallocs will prevent freeing to happen. I
believe therefore to be just easier to account this memory as global
overhead.
Signed-off-by: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Glauber Costa [Mon, 8 Jul 2013 23:00:00 +0000 (16:00 -0700)]
memcg: also test for skip accounting at the page allocation level
The memory we used to hold the memcg arrays is currently accounted to
the current memcg. But that creates a problem, because that memory can
only be freed after the last user is gone. Our only way to know which
is the last user, is to hook up to freeing time, but the fact that we
still have some in flight kmallocs will prevent freeing to happen. I
believe therefore to be just easier to account this memory as global
overhead.
This patch (of 2):
Disabling accounting is only relevant for some specific memcg internal
allocations. Therefore we would initially not have such check at
memcg_kmem_newpage_charge, since direct calls to the page allocator that
are marked with GFP_KMEMCG only happen outside memcg core. We are
mostly concerned with cache allocations and by having this test at
memcg_kmem_get_cache we are already able to relay the allocation to the
root cache and bypass the memcg caches altogether.
There is one exception, though: the SLUB allocator does not create large
order caches, but rather service large kmallocs directly from the page
allocator. Therefore, the following sequence, when backed by the SLUB
allocator:
would effectively ignore the fact that we should skip accounting, since
it will drive us directly to this function without passing through the
cache selector memcg_kmem_get_cache. Such large allocations are
extremely rare but can happen, for instance, for the cache arrays.
This was never a problem in practice, because we weren't skipping
accounting for the cache arrays. All the allocations we were skipping
were fairly small. However, the fact that we were not skipping those
allocations are a problem and can prevent the memcgs from going away.
As we fix that, we need to make sure that the fix will also work with
the SLUB allocator.
Signed-off-by: Glauber Costa <glommer@openvz.org> Reported-by: Michal Hocko <mhocko@suze.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info
We should check the VM_UNITIALIZED flag in s_show(). If this flag is
set, that said, the vm_struct is not fully initialized. So it is
unnecessary to try to show the information contained in vm_struct.
We checked this flag in show_numa_info(), but I think it's better to
check it earlier.
mm/vmalloc.c: rename VM_UNLIST to VM_UNINITIALIZED
VM_UNLIST was used to indicate that the vm_struct is not listed in
vmlist.
But after commit 4341fa454796 ("mm, vmalloc: remove list management of
vmlist after initializing vmalloc"), the meaning of this flag changed.
It now means the vm_struct is not fully initialized. So renaming it to
VM_UNINITIALIZED seems more reasonable.
Also change clear_vm_unlist to clear_vm_uninitialized_flag.
As we have removed the dead code in the vb_alloc, it seems there is no
place to use the alloc_map. So there is no reason to maintain the
alloc_map in vmap_block.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Space in a vmap block that was once allocated is considered dirty and
not made available for allocation again before the whole block is
recycled. The result is that free space within a vmap block is always
contiguous.
So if a vmap block has enough free space for allocation, the allocation
is impossible to fail. Thus, the fragmented block purging was never
invoked from vb_alloc(). So remove this dead code.
[ Same patches also sent by:
Chanho Min <chanho.min@lge.com>
Johannes Weiner <hannes@cmpxchg.org>
but git doesn't do "multiple authors" ]
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
That is to say, we call the get_pfn_range_for_nid to get start_pfn and
end_pfn of the node for MAX_NR_ZONES * 2 times. And this is totally
unnecessary if we call the get_pfn_range_for_nid before
zone_*_pages_in_node add two extra arguments node_start_pfn and
node_end_pfn for zone_*_pages_in_node, then we can remove the
get_pfn_range_in_node in zone_*_pages_in_node.
[akpm@linux-foundation.org: make definitions more readable] Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 8 Jul 2013 22:59:50 +0000 (15:59 -0700)]
mm: invoke oom-killer from remaining unconverted page fault handlers
A few remaining architectures directly kill the page faulting task in an
out of memory situation. This is usually not a good idea since that
task might not even use a significant amount of memory and so may not be
the optimal victim to resolve the situation.
Since 2.6.29's 1c0fe6e ("mm: invoke oom-killer from page fault") there
is a hook that architecture page fault handlers are supposed to call to
invoke the OOM killer and let it pick the right task to kill. Convert
the remaining architectures over to this hook.
To have the previous behavior of simply taking out the faulting task the
vm.oom_kill_allocating_task sysctl can be set to 1.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc bits] Cc: James Hogan <james.hogan@imgtec.com> Cc: David Howells <dhowells@redhat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 8 Jul 2013 22:59:49 +0000 (15:59 -0700)]
memcg: clean up memcg->nodeinfo
Remove struct mem_cgroup_lru_info and fold its single member, the
variably sized nodeinfo[0], directly into struct mem_cgroup. This
should make it more obvious why it has to be the last member there.
Also move the comment that's above that special last member below it, so
it is more visible to somebody that considers appending to the struct
mem_cgroup.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>