07 Apr, 2009
4 commits
-
Add /proc entries to give the admin the ability to control the minimum and
maximum number of pdflush threads. This allows finer control of pdflush
on both large and small machines.The rationale is simply one size does not fit all. Admins on large and/or
small systems may want to tune the min/max pdflush thread count to best
suit their needs. Right now the min/max is hardcoded to 2/8. While
probably a fair estimate for smaller machines, large machines with large
numbers of CPUs and large numbers of filesystems/block devices may benefit
from larger numbers of threads working on different block devices.Even if the background flushing algorithm is radically changed, it is
still likely that multiple threads will be involved and admins would still
desire finer control on the min/max other than to have to recompile the
kernel.The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and
'/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions.The minimum value for nr_pdflush_threads_min is 1 and the maximum value is
the current value of nr_pdflush_threads_max. This minimum is required
since additional thread creation is performed in a pdflush thread itself.The minimum value for nr_pdflush_threads_max is the current value of
nr_pdflush_threads_min and the maximum value can be 1000.Documentation/sysctl/vm.txt is also updated.
[akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly]
Signed-off-by: Peter W Morreale
Reviewed-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix a race on creating pdflush threads. Without the patch, it is possible
to create more than MAX_PDFLUSH_THREADS threads, and this has been
observed in practice on IO loaded SMP machines.The fix involves moving the lock around to protect the check against the
thread count and correctly dealing with thread creation failure.This fix also _mostly_ repairs a race condition on how quickly the threads
are created. The original intent was to create a pdflush thread (up to
the max allowed) every second. Without this patch is is possible to
create NCPUS pdflush threads concurrently. The 'mostly' caveat is because
an assumption is made that thread creation will be successful. If we fail
to create the thread, the miss is not considered fatal. (we will try
again in 1 second)Signed-off-by: Peter W Morreale
Reviewed-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This eliminates a compiler warning:
mm/allocpercpu.c: In function 'free_percpu':
mm/allocpercpu.c:146: warning: passing argument 2 of '__percpu_depopulate_mask' discards qualifiers from pointer target typeSigned-off-by: Stephen Rothwell
Signed-off-by: Linus Torvalds -
…git/tip/linux-2.6-tip
* 'kmemtrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
kmemtrace: trace kfree() calls with NULL or zero-length objects
kmemtrace: small cleanups
kmemtrace: restore original tracing data binary format, improve ABI
kmemtrace: kmemtrace_alloc() must fill type_id
kmemtrace: use tracepoints
kmemtrace, rcu: don't include unnecessary headers, allow kmemtrace w/ tracepoints
kmemtrace, rcu: fix rcupreempt.c data structure dependencies
kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies
kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies
kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_unlzma.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_bunzip2.c
kmemtrace, kbuild: fix slab.h dependency problem in lib/decompress_inflate.c
kmemtrace, squashfs: fix slab.h dependency problem in squasfs
kmemtrace, befs: fix slab.h dependency problem
kmemtrace, security: fix linux/key.h header file dependencies
kmemtrace, fs: fix linux/fdtable.h header file dependencies
kmemtrace, fs: uninline simple_transaction_set()
kmemtrace, fs, security: move alloc_secdata() and free_secdata() to linux/security.h
06 Apr, 2009
4 commits
-
This makes sure that we never wait on async IO for sync requests, instead
of doing the split on writes vs reads.Signed-off-by: Jens Axboe
Signed-off-by: Linus Torvalds -
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (714 commits)
Staging: sxg: slicoss: Specify the license for Sahara SXG and Slicoss drivers
Staging: serqt_usb: fix build due to proc tty changes
Staging: serqt_usb: fix checkpatch errors
Staging: serqt_usb: add TODO file
Staging: serqt_usb: Lindent the code
Staging: add USB serial Quatech driver
staging: document that the wifi staging drivers a bit better
Staging: echo cleanup
Staging: BUG to BUG_ON changes
Staging: remove some pointless conditionals before kfree_skb()
Staging: line6: fix build error, select SND_RAWMIDI
Staging: line6: fix checkpatch errors in variax.c
Staging: line6: fix checkpatch errors in toneport.c
Staging: line6: fix checkpatch errors in pcm.c
Staging: line6: fix checkpatch errors in midibuf.c
Staging: line6: fix checkpatch errors in midi.c
Staging: line6: fix checkpatch errors in dumprequest.c
Staging: line6: fix checkpatch errors in driver.c
Staging: line6: fix checkpatch errors in audio.c
Staging: line6: fix checkpatch errors in pod.c
... -
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c -
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
cpumask: remove cpumask allocation from idle_balance, fix
numa, cpumask: move numa_node_id default implementation to topology.h, fix
cpumask: remove cpumask allocation from idle_balance
x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
x86: microcode: cleanup
x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
numa, cpumask: move numa_node_id default implementation to topology.h
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
cpumask: remove x86 cpumask_t uses.
cpumask: use cpumask_var_t in uv_flush_tlb_others.
cpumask: remove cpumask_t assignment from vector_allocation_domain()
cpumask: make Xen use the new operators.
cpumask: clean up summit's send_IPI functions
cpumask: use new cpumask functions throughout x86
x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
x86: unify 32 and 64-bit node_to_cpumask_map
...
04 Apr, 2009
2 commits
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
... -
This patch adds Kconfig and Makefile entries and exports to
VFS functions to be used by POHMELFS.Signed-off-by: Evgeniy Polyakov
Signed-off-by: Greg Kroah-Hartman
03 Apr, 2009
22 commits
-
Add a function to install a monitor on the page lock waitqueue for a particular
page, thus allowing the page being unlocked to be detected.This is used by CacheFiles to detect read completion on a page in the backing
filesystem so that it can then copy the data to the waiting netfs page.Signed-off-by: David Howells
Acked-by: Steve Dickson
Acked-by: Trond Myklebust
Acked-by: Rik van Riel
Acked-by: Al Viro
Tested-by: Daire Byrne -
Recruit a page flag to aid in cache management. The following extra flag is
defined:(1) PG_fscache (PG_private_2)
The marked page is backed by a local cache and is pinning resources in the
cache driver.If PG_fscache is set, then things that checked for PG_private will now also
check for that. This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.Signed-off-by: David Howells
Acked-by: Steve Dickson
Acked-by: Trond Myklebust
Acked-by: Rik van Riel
Acked-by: Al Viro
Tested-by: Daire Byrne -
The attached patch causes read_cache_pages() to release page-private data on a
page for which add_to_page_cache() fails. If the filler function fails, then
the problematic page is left attached to the pagecache (with appropriate flags
set, one presumes) and the remaining to-be-attached pages are invalidated and
discarded. This permits pages with caching references associated with them to
be cleaned up.The invalidatepage() address space op is called (indirectly) to do the honours.
Signed-off-by: David Howells
Acked-by: Steve Dickson
Acked-by: Trond Myklebust
Acked-by: Rik van Riel
Acked-by: Al Viro
Tested-by: Daire Byrne -
Impact: also output kfree(NULL) entries
This patch moves the trace_kfree() calls before the ZERO_OR_NULL_PTR
check so that we can trace call-sites that call kfree() with NULL many
times which might be an indication of a bug.Signed-off-by: Pekka Enberg
Cc: Eduard - Gabriel Munteanu
LKML-Reference:
Signed-off-by: Ingo Molnar -
kmemtrace now uses tracepoints instead of markers. We no longer need to
use format specifiers to pass arguments.Signed-off-by: Eduard - Gabriel Munteanu
[ folded: Use the new TP_PROTO and TP_ARGS to fix the build. ]
[ folded: fix build when CONFIG_KMEMTRACE is disabled. ]
[ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ]
Signed-off-by: Pekka Enberg
LKML-Reference:
Signed-off-by: Ingo Molnar -
Impact: cleanup
mm/failslab.c depends on slab.h without including it:
CC mm/failslab.o
mm/failslab.c: In function ‘should_failslab’:
mm/failslab.c:16: error: ‘__GFP_NOFAIL’ undeclared (first use in this function)
mm/failslab.c:16: error: (Each undeclared identifier is reported only once
mm/failslab.c:16: error: for each function it appears in.)
mm/failslab.c:19: error: ‘__GFP_WAIT’ undeclared (first use in this function)
make[1]: *** [mm/failslab.o] Error 1
make: *** [mm] Error 2It gets included implicitly currently - but this will not be the
case with upcoming kmemtrace changes.Signed-off-by: Pekka Enberg
Cc: Eduard - Gabriel Munteanu
LKML-Reference:
Signed-off-by: Ingo Molnar -
Current mem_cgroup_cache_charge is a bit complicated especially
in the case of shmem's swap-in.This patch cleans it up by using try_charge_swapin and commit_charge_swapin.
Signed-off-by: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It's pointed out that swap_cgroup's message at swapon() is nonsense.
Because* It can be calculated very easily if all necessary information is
written in Kconfig.* It's not necessary to annoying people at every swapon().
In other view, now, memory usage per swp_entry is reduced to 2bytes from
8bytes(64bit) and I think it's reasonably small.Reported-by: Hugh Dickins
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine,
size of swap_cgroup goes down to 2 bytes from 8bytes.This means, when 2GB of swap is equipped, (assume the page size is 4096bytes)
From size of swap_cgroup = 2G/4k * 8 = 4Mbytes.
To size of swap_cgroup = 2G/4k * 2 = 1Mbytes.Reduction is large. Of course, there are trade-offs. This CSS ID will
add overhead to swap-in/swap-out/swap-free.But in general,
- swap is a resource which the user tend to avoid use.
- If swap is never used, swap_cgroup area is not used.
- Reading traditional manuals, size of swap should be proportional to
size of memory. Memory size of machine is increasing now.I think reducing size of swap_cgroup makes sense.
Note:
- ID->CSS lookup routine has no locks, it's under RCU-Read-Side.
- memcg can be obsolete at rmdir() but not freed while refcnt from
swap_cgroup is available.Changelog v4->v5:
- reworked on to memcg-charge-swapcache-to-proper-memcg.patch
Changlog ->v4:
- fixed not configured case.
- deleted unnecessary comments.
- fixed NULL pointer bug.
- fixed message in dmesg.[nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case]
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Balbir Singh
Cc: Paul Menage
Cc: Hugh Dickins
Signed-off-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
memcg_test.txt says at 4.1:
This swap-in is one of the most complicated work. In do_swap_page(),
following events occur when pte is unchanged.(1) the page (SwapCache) is looked up.
(2) lock_page()
(3) try_charge_swapin()
(4) reuse_swap_page() (may call delete_swap_cache())
(5) commit_charge_swapin()
(6) swap_free().Considering following situation for example.
(A) The page has not been charged before (2) and reuse_swap_page()
doesn't call delete_from_swap_cache().
(B) The page has not been charged before (2) and reuse_swap_page()
calls delete_from_swap_cache().
(C) The page has been charged before (2) and reuse_swap_page() doesn't
call delete_from_swap_cache().
(D) The page has been charged before (2) and reuse_swap_page() calls
delete_from_swap_cache().memory.usage/memsw.usage changes to this page/swp_entry will be
Case (A) (B) (C) (D)
Event
Before (2) 0/ 1 0/ 1 1/ 1 1/ 1
===========================================
(3) +1/+1 +1/+1 +1/+1 +1/+1
(4) - 0/ 0 - -1/ 0
(5) 0/-1 0/ 0 -1/-1 0/ 0
(6) - 0/-1 - 0/-1
===========================================
Result 1/ 1 1/ 1 1/ 1 1/ 1In any cases, charges to this page should be 1/ 1.
In case of (D), mem_cgroup_try_get_from_swapcache() returns NULL
(because lookup_swap_cgroup() returns NULL), so "+1/+1" at (3) means
charges to the memcg("foo") to which the "current" belongs.
OTOH, "-1/0" at (4) and "0/-1" at (6) means uncharges from the memcg("baa")
to which the page has been charged.So, if the "foo" and "baa" is different(for example because of task move),
this charge will be moved from "baa" to "foo".I think this is an unexpected behavior.
This patch fixes this by modifying mem_cgroup_try_get_from_swapcache()
to return the memcg to which the swapcache has been charged if PCG_USED bit
is set.
IIUC, checking PCG_USED bit of swapcache is safe under page lock.Signed-off-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, mem_cgroup_calc_mapped_ratio() is unused at all. it can be
removed and KAMEZAWA-san suggested it.Signed-off-by: KOSAKI Motohiro
Cc: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Cc: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add RSS and swap to OOM output from memcg
Display memcg values like failcnt, usage and limit when an OOM occurs due
to memcg.Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki,
Daisuke Nishimura and KOSAKI Motohiro for review.Sample output
-------------Task in /a/x killed as a result of limit of /a
memory: usage 1048576kB, limit 1048576kB, failcnt 4183
memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0[akpm@linux-foundation.org: compilation fix]
[akpm@linux-foundation.org: fix kerneldoc and whitespace]
[akpm@linux-foundation.org: add printk facility level]
Signed-off-by: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Li Zefan
Cc: Paul Menage
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch tries to fix OOM Killer problems caused by hierarchy.
Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to
kill a task in memcg.But, when hierarchy is used, it's broken and correct task cannot
be killed. For example, in following cgroup/groupA/ hierarchy=1, limit=1G,
01 nolimit
02 nolimit
All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to
groupA's 1Gbytes but OOM Killer just kills tasks in groupA.This patch provides makes the bad process be selected from all tasks
under hierarchy. BTW, currently, oom_jiffies is updated against groupA
in above case. oom_jiffies of tree should be updated.To see how oom_jiffies is used, please check mem_cgroup_oom_called()
callers.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: const fix]
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As pointed out, shrinking memcg's limit should return -EBUSY after
reasonable retries. This patch tries to fix the current behavior of
shrink_usage.Before looking into "shrink should return -EBUSY" problem, we should fix
hierarchical reclaim code. It compares current usage and current limit,
but it only makes sense when the kernel reclaims memory because hit
limits. This is also a problem.What this patch does are.
1. add new argument "shrink" to hierarchical reclaim. If "shrink==true",
hierarchical reclaim returns immediately and the caller checks the kernel
should shrink more or not.
(At shrinking memory, usage is always smaller than limit. So check for
usage < limit is useless.)2. For adjusting to above change, 2 changes in "shrink"'s retry path.
2-a. retry_count depends on # of children because the kernel visits
the children under hierarchy one by one.
2-b. rather than checking return value of hierarchical_reclaim's progress,
compares usage-before-shrink and usage-after-shrink.
If usage-before-shrink
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up memory.stat file routine and show "total" hierarchical stat.
This patch does
- renamed get_all_zonestat to be get_local_zonestat.
- remove old mem_cgroup_stat_desc, which is only for per-cpu stat.
- add mcs_stat to cover both of per-cpu/per-lru stat.
- add "total" stat of hierarchy (*)
- add a callback system to scan all memcg under a root.
== "total" is added.
[kamezawa@localhost ~]$ cat /opt/cgroup/xxx/memory.stat
cache 0
rss 0
pgpgin 0
pgpgout 0
inactive_anon 0
active_anon 0
inactive_file 0
active_file 0
unevictable 0
hierarchical_memory_limit 50331648
hierarchical_memsw_limit 9223372036854775807
total_cache 65536
total_rss 192512
total_pgpgin 218
total_pgpgout 155
total_inactive_anon 0
total_active_anon 135168
total_inactive_file 61440
total_active_file 4096
total_unevictable 0
==
(*) maybe the user can do calc hierarchical stat by his own program
in userland but if it can be written in clean way, it's worth to be
shown, I think.Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Assigning CSS ID for each memcg and use css_get_next() for scanning hierarchy.
Assume folloing tree.
group_A (ID=3)
/01 (ID=4)
/0A (ID=7)
/02 (ID=10)
group_B (ID=5)
and task in group_A/01/0A hits limit at group_A.reclaim will be done in following order (round-robin).
group_A(3) -> group_A/01 (4) -> group_A/01/0A (7) -> group_A/02(10)
-> group_A -> .....Round robin by ID. The last visited cgroup is recorded and restart
from it when it start reclaim again.
(More smart algorithm can be implemented..)No cgroup_mutex or hierarchy_mutex is required.
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In following situation, with memory subsystem,
/groupA use_hierarchy==1
/01 some tasks
/02 some tasks
/03 some tasks
/04 emptyWhen tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim
is triggered and the kernel walks tree under groupA. In this case,
rmdir /groupA/04 fails with -EBUSY frequently because of temporal
refcnt from the kernel.In general. cgroup can be rmdir'd if there are no children groups and
no tasks. Frequent fails of rmdir() is not useful to users.
(And the reason for -EBUSY is unknown to users.....in most cases)This patch tries to modify above behavior, by
- retries if css_refcnt is got by someone.
- add "return value" to pre_destroy() and allows subsystem to
say "we're really busy!"Signed-off-by: KAMEZAWA Hiroyuki
Cc: Paul Menage
Cc: Li Zefan
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It is a fairly common operation to have a pointer to a work and to need a
pointer to the delayed work it is contained in. In particular, all
delayed works which want to rearm themselves will have to do that. So it
would seem fair to offer a helper function for this operation.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jean Delvare
Acked-by: Ingo Molnar
Cc: "David S. Miller"
Cc: Herbert Xu
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Greg KH
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The calculation of the value nr in do_xip_mapping_read is incorrect. If
the copy required more than one iteration in the do while loop the copies
variable will be non-zero. The maximum length that may be passed to the
call to copy_to_user(buf+copied, xip_mem+offset, nr) is len-copied but the
check only compares against (nr > len).This bug is the cause for the heap corruption Carsten has been chasing
for so long:*** glibc detected *** /bin/bash: free(): invalid next size (normal): 0x00000000800e39f0 ***
======= Backtrace: =========
/lib64/libc.so.6[0x200000b9b44]
/lib64/libc.so.6(cfree+0x8e)[0x200000bdade]
/bin/bash(free_buffered_stream+0x32)[0x80050e4e]
/bin/bash(close_buffered_stream+0x1c)[0x80050ea4]
/bin/bash(unset_bash_input+0x2a)[0x8001c366]
/bin/bash(make_child+0x1d4)[0x8004115c]
/bin/bash[0x8002fc3c]
/bin/bash(execute_command_internal+0x656)[0x8003048e]
/bin/bash(execute_command+0x5e)[0x80031e1e]
/bin/bash(execute_command_internal+0x79a)[0x800305d2]
/bin/bash(execute_command+0x5e)[0x80031e1e]
/bin/bash(reader_loop+0x270)[0x8001efe0]
/bin/bash(main+0x1328)[0x8001e960]
/lib64/libc.so.6(__libc_start_main+0x100)[0x200000592a8]
/bin/bash(clearerr+0x5e)[0x8001c092]With this bug fix the commit 0e4a9b59282914fe057ab17027f55123964bc2e2
"ext2/xip: refuse to change xip flag during remount with busy inodes" can
be removed again.Cc: Carsten Otte
Cc: Nick Piggin
Cc: Jared Hulbert
Cc:
Signed-off-by: Martin Schwidefsky
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Even though vmstat_work is marked deferrable, there are still benefits to
aligning it. For certain applications we want to keep OS jitter as low as
possible and aligning timers and work so they occur together can reduce
their overall impact.Signed-off-by: Anton Blanchard
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix a number of issues with the per-MM VMA patch:
(1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
a NOMMU system with more than 2G pages. Makes no difference on a 32-bit
system.(2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
lest it overflow.(3) Move the allocation of the vm_area_struct slab back for fork.c.
(4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.
(5) Use BUG_ON() rather than if () BUG().
(6) Make the default validate_nommu_regions() a static inline rather than a
#define.(7) Make free_page_series()'s objection to pages with a refcount != 1 more
informative.(8) Adjust the __put_nommu_region() banner comment to indicate that the
semaphore must be held for writing.(9) Limit the number of warnings about munmaps of non-mmapped regions.
Reported-by: Andrew Morton
Signed-off-by: David Howells
Cc: Greg Ungerer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This fixes a build failure with generic debug pagealloc:
mm/debug-pagealloc.c: In function 'set_page_poison':
mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'clear_page_poison':
mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: In function 'page_poison':
mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
mm/debug-pagealloc.c: At top level:
mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
include/linux/mm.h:1278: error: previous definition of 'kernel_map_pages' was here
mm/debug-pagealloc.c: In function 'kernel_map_pages':
mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared (first use in this function)by fixing
- debug_flags should be in struct page
- define DEBUG_PAGEALLOC config option for all architecturesSigned-off-by: Akinobu Mita
Reported-by: Alexander Beregalov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Apr, 2009
1 commit
-
Conflicts:
include/linux/slub_def.h
lib/Kconfig.debug
mm/slob.c
mm/slub.c
01 Apr, 2009
7 commits
-
Synopsis: if shmem_writepage calls swap_writepage directly, most shmem
swap loads benefit, and a catastrophic interaction between SLUB and some
flash storage is avoided.shmem_writepage() has always been peculiar in making no attempt to write:
it has just transferred a shmem page from file cache to swap cache, then
let that page make its way around the LRU again before being written and
freed.The idea was that people use tmpfs because they want those pages to stay
in RAM; so although we give it an overflow to swap, we should resist
writing too soon, giving those pages a second chance before they can be
reclaimed.That was always questionable, and I've toyed with this patch for years;
but never had a clear justification to depart from the original design.It became more questionable in 2.6.28, when the split LRU patches classed
shmem and tmpfs pages as SwapBacked rather than as file_cache: that in
itself gives them more resistance to reclaim than normal file pages. I
prepared this patch for 2.6.29, but the merge window arrived before I'd
completed gathering statistics to justify sending it in.Then while comparing SLQB against SLUB, running SLUB on a laptop I'd
habitually used with SLAB, I found SLUB to run my tmpfs kbuild swapping
tests five times slower than SLAB or SLQB - other machines slower too, but
nowhere near so bad. Simpler "cp -a" swapping tests showed the same.slub_max_order=0 brings sanity to all, but heavy swapping is too far from
normal to justify such a tuning. The crucial factor on that laptop turns
out to be that I'm using an SD card for swap. What happens is this:By default, SLUB uses order-2 pages for shmem_inode_cache (and many other
fs inodes), so creating tmpfs files under memory pressure brings lumpy
reclaim into play. One subpage of the order is chosen from the bottom of
the LRU as usual, then the other three picked out from their random
positions on the LRUs.In a tmpfs load, many of these pages will be ones which already passed
through shmem_writepage, so already have swap allocated. And though their
offsets on swap were probably allocated sequentially, now that the pages
are picked off at random, their swap offsets are scattered.But the flash storage on the SD card is very sensitive to having its
writes merged: once swap is written at scattered offsets, performance
falls apart. Rotating disk seeks increase too, but less disastrously.So: stop giving shmem/tmpfs pages a second pass around the LRU, write them
out to swap as soon as their swap has been allocated.It's surely possible to devise an artificial load which runs faster the
old way, one whose sizing is such that the tmpfs pages on their second
pass are the ones that are wanted again, and other pages not.But I've not yet found such a load: on all machines, under the loads I've
tried, immediate swap_writepage speeds up shmem swapping: especially when
using the SLUB allocator (and more effectively than slub_max_order=0), but
also with the others; and it also reduces the variance between runs. How
much faster varies widely: a factor of five is rare, 5% is common.One load which might have suffered: imagine a swapping shmem load in a
limited mem_cgroup on a machine with plenty of memory. Before 2.6.29 the
swapcache was not charged, and such a load would have run quickest with
the shmem swapcache never written to swap. But now swapcache is charged,
so even this load benefits from shmem_writepage directly to swap.Apologies for the #ifndef CONFIG_SWAP swap_writepage() stub in swap.h:
it's silly because that will never get called; but refactoring shmem.c
sensibly according to CONFIG_SWAP will be a separate task.Signed-off-by: Hugh Dickins
Acked-by: Pekka Enberg
Acked-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
try_to_free_pages() is used for the direct reclaim of up to
SWAP_CLUSTER_MAX pages when watermarks are low. The caller to
alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to
be used but this is not passed to try_to_free_pages(). This can lead to
unnecessary reclaim of pages that are unusable by the caller and int the
worst case lead to allocation failure as progress was not been make where
it is needed.This patch passes the nodemask used for alloc_pages_nodemask() to
try_to_free_pages().Reviewed-by: KOSAKI Motohiro
Acked-by: Mel Gorman
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When a shrinker has a negative number of objects to delete, the symbol
name of the shrinker should be printed, not shrink_slab. This also makes
the error message slightly more informative.Cc: Ingo Molnar
Signed-off-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n. There's no logical
reason it shouldn't be available, and it can be used for ramfs.Signed-off-by: David Howells
Reviewed-by: KOSAKI Motohiro
Cc: Peter Zijlstra
Cc: Greg Ungerer
Cc: Johannes Weiner
Cc: Rik van Riel
Cc: Lee Schermerhorn
Cc: Enrik Berkhan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The mlock() facility does not exist for NOMMU since all mappings are
effectively locked anyway, so we don't make the bits available when
they're not useful.Signed-off-by: David Howells
Reviewed-by: KOSAKI Motohiro
Cc: Peter Zijlstra
Cc: Greg Ungerer
Cc: Johannes Weiner
Cc: Rik van Riel
Cc: Lee Schermerhorn
Cc: Enrik Berkhan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic. It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.This patch exposes it to the other architectures.
Signed-off-by: Akinobu Mita
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags. There should be no functional change.This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg. virtual_address to the
driver, which might be important in some special cases).This is required for a subsequent fix. And will also make it easier to
merge page_mkwrite() with fault() in future.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Trond Myklebust
Cc: Miklos Szeredi
Cc: Steven Whitehouse
Cc: Mark Fasheh
Cc: Joel Becker
Cc: Artem Bityutskiy
Cc: Felix Blyakher
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
