30 Jan, 2010
1 commit
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After memory pressure has forced it to dip into the reserves, 2.6.32's
5f8dcc21211a3d4e3a7a5ca366b469fb88117f61 "page-allocator: split per-cpu
list into one-list-per-migrate-type" has been returning MIGRATE_RESERVE
pages to the MIGRATE_MOVABLE free_list: in some sense depleting reserves.Fix that in the most straightforward way (which, considering the overheads
of alternative approaches, is Mel's preference): the right migratetype is
already in page_private(page), but free_pcppages_bulk() wasn't using it.How did this bug show up? As a 20% slowdown in my tmpfs loop kbuild
swapping tests, on PowerMac G5 with SLUB allocator. Bisecting to that
commit was easy, but explaining the magnitude of the slowdown not easy.The same effect appears, but much less markedly, with SLAB, and even
less markedly on other machines (the PowerMac divides into fewer zones
than x86, I think that may be a factor). We guess that lumpy reclaim
of short-lived high-order pages is implicated in some way, and probably
this bug has been tickling a poor decision somewhere in page reclaim.But instrumentation hasn't told me much, I've run out of time and
imagination to determine exactly what's going on, and shouldn't hold up
the fix any longer: it's valid, and might even fix other misbehaviours.Signed-off-by: Hugh Dickins
Acked-by: Mel Gorman
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds
17 Jan, 2010
2 commits
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commit f2260e6b (page allocator: update NR_FREE_PAGES only as necessary)
made one minor regression. if __rmqueue() was failed, NR_FREE_PAGES stat
go wrong. this patch fixes it.Signed-off-by: KOSAKI Motohiro
Cc: Mel Gorman
Reviewed-by: Minchan Kim
Reported-by: Huang Shijie
Reviewed-by: Christoph Lameter
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The current check for 'backward merging' within add_active_range() does
not seem correct. start_pfn must be compared against
early_node_map[i].start_pfn (and NOT against .end_pfn) to find out whether
the new region is backward-mergeable with the existing range.Signed-off-by: Kazuhisa Ichikawa
Acked-by: David Rientjes
Cc: KOSAKI Motohiro
Cc: Mel Gorman
Cc: Christoph Lameter
Cc: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Dec, 2009
1 commit
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The zone list code clearly cannot tolerate concurrent writers (I couldn't
find any locks for that), so simply add a global mutex. No need for RCU
in this case.Signed-off-by: Andi Kleen
23 Dec, 2009
1 commit
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* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits)
powerpc/gc/wii: Remove get_irq_desc()
powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock
powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg
powerpc/mpic: Fix problem that affinity is not updated
powerpc/mm: Fix stupid bug in subpge protection handling
powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion
powerpc: Fix MSI support on U4 bridge PCIe slot
powerpc: Handle VSX alignment faults correctly in little-endian mode
powerpc/mm: Fix typo of cpumask_clear_cpu()
powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled.
powerpc: Convert BUG() to use unreachable()
powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible.
powerpc/pseries: Don't panic when H_PROD fails during cpu-online.
powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM
powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs
powerpc/defconfigs: Disable token ring in powerpc defconfigs
powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules
powerpc/pseries: Select XICS and PCI_MSI PSERIES
powerpc/85xx: Wrong variable returned on error
powerpc/iseries: Convert to proc_fops
...
20 Dec, 2009
1 commit
-
…git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system
Makefile: Unexport LC_ALL instead of clearing it
x86: Fix objdump version check in arch/x86/tools/chkobjdump.awk
x86: Reenable TSC sync check at boot, even with NONSTOP_TSC
x86: Don't use POSIX character classes in gen-insn-attr-x86.awk
Makefile: set LC_CTYPE, LC_COLLATE, LC_NUMERIC to C
x86: Increase MAX_EARLY_RES; insufficient on 32-bit NUMA
x86: Fix checking of SRAT when node 0 ram is not from 0
x86, cpuid: Add "volatile" to asm in native_cpuid()
x86, msr: msrs_alloc/free for CONFIG_SMP=n
x86, amd: Get multi-node CPU info from NodeId MSR instead of PCI config space
x86: Add IA32_TSC_AUX MSR and use it
x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers
initramfs: add missing decompressor error check
bzip2: Add missing checks for malloc returning NULL
bzip2/lzma/gzip: pre-boot malloc doesn't return NULL on failure
18 Dec, 2009
1 commit
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Memory balloon drivers can allocate a large amount of memory which is not
movable but could be freed to accomodate memory hotplug remove.Prior to calling the memory hotplug notifier chain the memory in the
pageblock is isolated. Currently, if the migrate type is not
MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal
for that page range to fail.Rather than failing pageblock isolation if the migrateteype is not
MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock,
and not on the LRU, are owned by a registered balloon driver (or other
entity) using a notifier chain. If all of the non-movable pages are owned
by a balloon, they can be freed later through the memory notifier chain
and the range can still be isolated in set_migratetype_isolate().Signed-off-by: Robert Jennings
Cc: Mel Gorman
Cc: Ingo Molnar
Cc: Brian King
Cc: Paul Mackerras
Cc: Martin Schwidefsky
Cc: Gerald Schaefer
Cc: KAMEZAWA Hiroyuki
Cc: Benjamin Herrenschmidt
Signed-off-by: Andrew Morton
Signed-off-by: Benjamin Herrenschmidt
17 Dec, 2009
2 commits
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Found one system that boot from socket1 instead of socket0, SRAT get rejected...
[ 0.000000] SRAT: Node 1 PXM 0 0-a0000
[ 0.000000] SRAT: Node 1 PXM 0 100000-80000000
[ 0.000000] SRAT: Node 1 PXM 0 100000000-2080000000
[ 0.000000] SRAT: Node 0 PXM 1 2080000000-4080000000
[ 0.000000] SRAT: Node 2 PXM 2 4080000000-6080000000
[ 0.000000] SRAT: Node 3 PXM 3 6080000000-8080000000
[ 0.000000] SRAT: Node 4 PXM 4 8080000000-a080000000
[ 0.000000] SRAT: Node 5 PXM 5 a080000000-c080000000
[ 0.000000] SRAT: Node 6 PXM 6 c080000000-e080000000
[ 0.000000] SRAT: Node 7 PXM 7 e080000000-10080000000
...
[ 0.000000] NUMA: Allocated memnodemap from 500000 - 701040
[ 0.000000] NUMA: Using 20 for the hash shift.
[ 0.000000] Adding active range (0, 0x2080000, 0x4080000) 0 entries of 3200 used
[ 0.000000] Adding active range (1, 0x0, 0x96) 1 entries of 3200 used
[ 0.000000] Adding active range (1, 0x100, 0x7f750) 2 entries of 3200 used
[ 0.000000] Adding active range (1, 0x100000, 0x2080000) 3 entries of 3200 used
[ 0.000000] Adding active range (2, 0x4080000, 0x6080000) 4 entries of 3200 used
[ 0.000000] Adding active range (3, 0x6080000, 0x8080000) 5 entries of 3200 used
[ 0.000000] Adding active range (4, 0x8080000, 0xa080000) 6 entries of 3200 used
[ 0.000000] Adding active range (5, 0xa080000, 0xc080000) 7 entries of 3200 used
[ 0.000000] Adding active range (6, 0xc080000, 0xe080000) 8 entries of 3200 used
[ 0.000000] Adding active range (7, 0xe080000, 0x10080000) 9 entries of 3200 used
[ 0.000000] SRAT: PXMs only cover 917504MB of your 1048566MB e820 RAM. Not used.
[ 0.000000] SRAT: SRAT not used.the early_node_map is not sorted because node0 with non zero start come first.
so try to sort it right away after all regions are registered.
also fixs refression by 8716273c (x86: Export srat physical topology)
-v2: make it more solid to handle cross node case like node0 [0,4g), [8,12g) and node1 [4g, 8g), [12g, 16g)
-v3: update comments.Reported-and-tested-by: Jens Axboe
Signed-off-by: Yinghai Lu
LKML-Reference:
Signed-off-by: H. Peter Anvin -
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits)
HWPOISON: Remove stray phrase in a comment
HWPOISON: Try to allocate migration page on the same node
HWPOISON: Don't do early filtering if filter is disabled
HWPOISON: Add a madvise() injector for soft page offlining
HWPOISON: Add soft page offline support
HWPOISON: Undefine short-hand macros after use to avoid namespace conflict
HWPOISON: Use new shake_page in memory_failure
HWPOISON: Use correct name for MADV_HWPOISON in documentation
HWPOISON: mention HWPoison in Kconfig entry
HWPOISON: Use get_user_page_fast in hwpoison madvise
HWPOISON: add an interface to switch off/on all the page filters
HWPOISON: add memory cgroup filter
memcg: add accessor to mem_cgroup.css
memcg: rename and export try_get_mem_cgroup_from_page()
HWPOISON: add page flags filter
mm: export stable page flags
HWPOISON: limit hwpoison injector to known page types
HWPOISON: add fs/device filters
HWPOISON: return 0 to indicate success reliably
HWPOISON: make semantics of IGNORED/DELAYED clear
...
16 Dec, 2009
3 commits
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Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.In these days, things are changed as
- alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
- mempolicy don't maintain its own private zonelists.
(And cpuset doesn't use nodemask for __alloc_pages_nodemask())So, current oom-killer's check function is wrong.
This patch does
- check nodemask, if nodemask && nodemask doesn't cover all
node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
- Scan all zonelist under nodemask, if it hits cpuset's wall
this faiulre is from cpuset.
And
- modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
This doesn't change "current" behavior. If callers use __GFP_THISNODE
it should handle "page allocation failure" by itself.- handle __GFP_NOFAIL+__GFP_THISNODE path.
This is something like a FIXME but this gfpmask is not used now.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki
Acked-by: David Rientjes
Cc: Daisuke Nishimura
Cc: KOSAKI Motohiro
Cc: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Most free pages in the buddy system have no PG_buddy set.
Introduce is_free_buddy_page() for detecting them reliably.CC: Nick Piggin
CC: Mel Gorman
Signed-off-by: Wu Fengguang
Signed-off-by: Andi Kleen -
Remove three degrees of obfuscation, left over from when we had
CONFIG_UNEVICTABLE_LRU. MLOCK_PAGES is CONFIG_HAVE_MLOCKED_PAGE_BIT is
CONFIG_HAVE_MLOCK is CONFIG_MMU. rmap.o (and memory-failure.o) are only
built when CONFIG_MMU, so don't need such conditions at all.Somehow, I feel no compulsion to remove the CONFIG_HAVE_MLOCK* lines from
169 defconfigs: leave those to evolve in due course.Signed-off-by: Hugh Dickins
Cc: Izik Eidus
Cc: Andrea Arcangeli
Cc: Nick Piggin
Reviewed-by: KOSAKI Motohiro
Cc: Rik van Riel
Cc: Lee Schermerhorn
Cc: Andi Kleen
Cc: KAMEZAWA Hiroyuki
Cc: Wu Fengguang
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Nov, 2009
2 commits
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Commit 341ce06f69abfafa31b9468410a13dbd60e2b237 ("page allocator:
calculate the alloc_flags for allocation only once") altered watermark
logic slightly by allowing rt_tasks that are handling an interrupt to set
ALLOC_HARDER. This patch brings the watermark logic more in line with
2.6.30.This change results in a reduction of the number high-order GFP_ATOMIC
allocation failures reported. See
http://www.gossamer-threads.com/lists/linux/kernel/1144153[rientjes@google.com: Spotted the problem]
Signed-off-by: Mel Gorman
Reviewed-by: Pekka Enberg
Reviewed-by: Rik van Riel
Reviewed-by: KOSAKI Motohiro
Cc: David Rientjes
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If a direct reclaim makes no forward progress, it considers whether it
should go OOM or not. Whether OOM is triggered or not, it may retry the
allocation afterwards. In times past, this would always wake kswapd as
well but currently, kswapd is not woken up after direct reclaim fails.
For order-0 allocations, this makes little difference but if there is a
heavy mix of higher-order allocations that direct reclaim is failing for,
it might mean that kswapd is not rewoken for higher orders as much as it
did previously.This patch wakes up kswapd when an allocation is being retried after a
direct reclaim failure. It would be expected that kswapd is already
awake, but this has the effect of telling kswapd to reclaim at the higher
order as well.Signed-off-by: Mel Gorman
Reviewed-by: Christoph Lameter
Reviewed-by: Pekka Enberg
Reviewed-by: KOSAKI Motohiro
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2009
1 commit
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Revert
commit 71de1ccbe1fb40203edd3beb473f8580d917d2ca
Author: KOSAKI Motohiro
AuthorDate: Mon Sep 21 17:01:31 2009 -0700
Commit: Linus Torvalds
CommitDate: Tue Sep 22 07:17:27 2009 -0700mm: oom analysis: add buffer cache information to show_free_areas()
show_free_areas() is called during page allocation failures, and page
allocation failures can occur in any calling context.But nr_blockdev_pages() takes VFS locks which should not be taken from
hard IRQ context (at least). The result is lockdep warnings (and
deadlockability) during page allocation failures.Cc: KOSAKI Motohiro
Cc: Wu Fengguang
Cc: Rik van Riel
Cc: David Rientjes
Cc: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Sep, 2009
2 commits
-
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
HWPOISON: Enable error_remove_page on btrfs
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
HWPOISON: Add madvise() based injector for hardware poisoned pages v4
HWPOISON: Enable error_remove_page for NFS
HWPOISON: Enable .remove_error_page for migration aware file systems
HWPOISON: The high level memory error handler in the VM v7
HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
HWPOISON: shmem: call set_page_dirty() with locked page
HWPOISON: Define a new error_remove_page address space op for async truncation
HWPOISON: Add invalidate_inode_page
HWPOISON: Refactor truncate to allow direct truncating of page v2
HWPOISON: check and isolate corrupted free pages v2
HWPOISON: Handle hardware poisoned pages in try_to_unmap
HWPOISON: Use bitmask/action code for try_to_unmap behaviour
HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
HWPOISON: Add poison check to page fault handling
HWPOISON: Add basic support for poisoned pages in fault handler v3
HWPOISON: Add new SIGBUS error codes for hardware poison signals
HWPOISON: Add support for poison swap entries v2
HWPOISON: Export some rmap vma locking to outside world
... -
It's unused.
It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.It _was_ used in two places at arch/frv for some reason.
Signed-off-by: Alexey Dobriyan
Cc: David Howells
Cc: "Eric W. Biederman"
Cc: Al Viro
Cc: Ralf Baechle
Cc: Martin Schwidefsky
Cc: Ingo Molnar
Cc: "David S. Miller"
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Sep, 2009
23 commits
-
Move highest_memmap_pfn __read_mostly from page_alloc.c next to zero_pfn
__read_mostly in memory.c: to help them share a cacheline, since they're
very often tested together in vm_normal_page().Signed-off-by: Hugh Dickins
Cc: Rik van Riel
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Cc: Mel Gorman
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When round-robin freeing pages from the PCP lists, empty lists may be
encountered. In the event one of the lists has more pages than another,
there may be numerous checks for list_empty() which is undesirable. This
patch maintains a count of pages to free which is incremented when empty
lists are encountered. The intention is that more pages will then be
freed from fuller lists than the empty ones reducing the number of empty
list checks in the free path.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman
Cc: Nick Piggin
Cc: Christoph Lameter
Reviewed-by: Minchan Kim
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The following two patches remove searching in the page allocator fast-path
by maintaining multiple free-lists in the per-cpu structure. At the time
the search was introduced, increasing the per-cpu structures would waste a
lot of memory as per-cpu structures were statically allocated at
compile-time. This is no longer the case.The patches are as follows. They are based on mmotm-2009-08-27.
Patch 1 adds multiple lists to struct per_cpu_pages, one per
migratetype that can be stored on the PCP lists.Patch 2 notes that the pcpu drain path check empty lists multiple times. The
patch reduces the number of checks by maintaining a count of free
lists encountered. Lists containing pages will then free multiple
pages in batchThe patches were tested with kernbench, netperf udp/tcp, hackbench and
sysbench. The netperf tests were not bound to any CPU in particular and
were run such that the results should be 99% confidence that the reported
results are within 1% of the estimated mean. sysbench was run with a
postgres background and read-only tests. Similar to netperf, it was run
multiple times so that it's 99% confidence results are within 1%. The
patches were tested on x86, x86-64 and ppc64 asx86: Intel Pentium D 3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.34% to 2.28% gain
netperf-tcp - 0.45% to 1.22% gain
hackbench - Small variances, very close to noise
sysbench - Very small gainsx86-64: AMD Phenom 9950 1.3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.83% to 10.42% gains
netperf-tcp - No conclusive until buffer >= PAGE_SIZE
4096 +15.83%
8192 + 0.34% (not significant)
16384 + 1%
hackbench - Small gains, very close to noise
sysbench - 0.79% to 1.6% gainppc64: PPC970MP 2.5GHz with 10GB RAM (it's a terrasoft powerstation)
kernbench - No significant difference, variance well within noise
netperf-udp - 2-3% gain for almost all buffer sizes tested
netperf-tcp - losses on small buffers, gains on larger buffers
possibly indicates some bad caching effect.
hackbench - No significant difference
sysbench - 2-4% gainThis patch:
Currently the per-cpu page allocator searches the PCP list for pages of
the correct migrate-type to reduce the possibility of pages being
inappropriate placed from a fragmentation perspective. This search is
potentially expensive in a fast-path and undesirable. Splitting the
per-cpu list into multiple lists increases the size of a per-cpu structure
and this was potentially a major problem at the time the search was
introduced. These problem has been mitigated as now only the necessary
number of structures is allocated for the running system.This patch replaces a list search in the per-cpu allocator with one list
per migrate type. The potential snag with this approach is when bulk
freeing pages. We round-robin free pages based on migrate type which has
little bearing on the cache hotness of the page and potentially checks
empty lists repeatedly in the event the majority of PCP pages are of one
type.Signed-off-by: Mel Gorman
Acked-by: Nick Piggin
Cc: Christoph Lameter
Cc: Minchan Kim
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
For mem_cgroup, shrink_zone() may call shrink_list() with nr_to_scan=1, in
which case shrink_list() _still_ calls isolate_pages() with the much
larger SWAP_CLUSTER_MAX. It effectively scales up the inactive list scan
rate by up to 32 times.For example, with 16k inactive pages and DEF_PRIORITY=12, (16k >> 12)=4.
So when shrink_zone() expects to scan 4 pages in the active/inactive list,
the active list will be scanned 4 pages, while the inactive list will be
(over) scanned SWAP_CLUSTER_MAX=32 pages in effect. And that could break
the balance between the two lists.It can further impact the scan of anon active list, due to the anon
active/inactive ratio rebalance logic in balance_pgdat()/shrink_zone():inactive anon list over scanned => inactive_anon_is_low() == TRUE
=> shrink_active_list()
=> active anon list over scannedSo the end result may be
- anon inactive => over scanned
- anon active => over scanned (maybe not as much)
- file inactive => over scanned
- file active => under scanned (relatively)The accesses to nr_saved_scan are not lock protected and so not 100%
accurate, however we can tolerate small errors and the resulted small
imbalanced scan rates between zones.Cc: Rik van Riel
Reviewed-by: KOSAKI Motohiro
Acked-by: Balbir Singh
Reviewed-by: Minchan Kim
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Wu Fengguang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This is being done by allowing boot time allocations to specify that they
may want a sub-page sized amount of memory.Overall this seems more consistent with the other hash table allocations,
and allows making two supposedly mm-only variables really mm-only
(nr_{kernel,all}_pages).Signed-off-by: Jan Beulich
Cc: Ingo Molnar
Cc: "Eric W. Biederman"
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After anti-fragmentation was merged, a bug was reported whereby devices
that depended on high-order atomic allocations were failing. The solution
was to preserve a property in the buddy allocator which tended to keep the
minimum number of free pages in the zone at the lower physical addresses
and contiguous. To preserve this property, MIGRATE_RESERVE was introduced
and a number of pageblocks at the start of a zone would be marked
"reserve", the number of which depended on min_free_kbytes.Anti-fragmentation works by avoiding the mixing of page migratetypes
within the same pageblock. One way of helping this is to increase
min_free_kbytes because it becomes less like that it will be necessary to
place pages of of MIGRATE_RESERVE is unbounded, the free memory is kept
there in large contiguous blocks instead of helping anti-fragmentation as
much as it should. With the page-allocator tracepoint patches applied, it
was found during anti-fragmentation tests that the number of
fragmentation-related events were far higher than expected even with
min_free_kbytes at higher values.This patch limits the number of MIGRATE_RESERVE blocks that exist per zone
to two. For example, with a sufficient min_free_kbytes, 4MB of memory
will be kept aside on an x86-64 and remain more or less free and
contiguous for the systems uptime. This should be sufficient for devices
depending on high-order atomic allocations while helping fragmentation
control when min_free_kbytes is tuned appropriately. As side-effect of
this patch is that the reserve variable is converted to int as unsigned
long was the wrong type to use when ensuring that only the required number
of reserve blocks are created.With the patches applied, fragmentation-related events as measured by the
page allocator tracepoints were significantly reduced when running some
fragmentation stress-tests on systems with min_free_kbytes tuned to a
value appropriate for hugepage allocations at runtime. On x86, the events
recorded were reduced by 99.8%, on x86-64 by 99.72% and on ppc64 by
99.83%.Signed-off-by: Mel Gorman
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The page allocation trace event reports that a page was successfully
allocated but it does not specify where it came from. When analysing
performance, it can be important to distinguish between pages coming from
the per-cpu allocator and pages coming from the buddy lists as the latter
requires the zone lock to the taken and more data structures to be
examined.This patch adds a trace event for __rmqueue reporting when a page is being
allocated from the buddy lists. It distinguishes between being called to
refill the per-cpu lists or whether it is a high-order allocation.
Similarly, this patch adds an event to catch when the PCP lists are being
drained a little and pages are going back to the buddy lists.This is trickier to draw conclusions from but high activity on those
events could explain why there were a large number of cache misses on a
page-allocator-intensive workload. The coalescing and splitting of
buddies involves a lot of writing of page metadata and cache line bounces
not to mention the acquisition of an interrupt-safe lock necessary to
enter this path.[akpm@linux-foundation.org: fix build]
Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fragmentation avoidance depends on being able to use free pages from lists
of the appropriate migrate type. In the event this is not possible,
__rmqueue_fallback() selects a different list and in some circumstances
change the migratetype of the pageblock. Simplistically, the more times
this event occurs, the more likely that fragmentation will be a problem
later for hugepage allocation at least but there are other considerations
such as the order of page being split to satisfy the allocation.This patch adds a trace event for __rmqueue_fallback() that reports what
page is being used for the fallback, the orders of relevant pages, the
desired migratetype and the migratetype of the lists being used, whether
the pageblock changed type and whether this event is important with
respect to fragmentation avoidance or not. This information can be used
to help analyse fragmentation avoidance and help decide whether
min_free_kbytes should be increased or not.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds trace events for the allocation and freeing of pages,
including the freeing of pagevecs. Using the events, it will be known
what struct page and pfns are being allocated and freed and what the call
site was in many cases.The page alloc tracepoints be used as an indicator as to whether the
workload was heavily dependant on the page allocator or not. You can make
a guess based on vmstat but you can't get a per-process breakdown.
Depending on the call path, the call_site for page allocation may be
__get_free_pages() instead of a useful callsite. Instead of passing down
a return address similar to slab debugging, the user should enable the
stacktrace and seg-addr options to get a proper stack trace.The pagevec free tracepoint has a different usecase. It can be used to
get a idea of how many pages are being dumped off the LRU and whether it
is kswapd doing the work or a process doing direct reclaim.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The function free_cold_page() has no callers so delete it.
Signed-off-by: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
…uring __rmqueue_fallback
When there are no pages of a target migratetype free, the page allocator
selects a high-order block of another migratetype to allocate from. When
the order of the page taken is greater than pageblock_order, all
pageblocks within that high-order page should change migratetype so that
pages are later freed to the correct free-lists.The current behaviour is that pageblocks change migratetype if the order
being split matches the pageblock_order. When pageblock_order <
MAX_ORDER-1, ownership is not changing correct and pages are being later
freed to the incorrect list and this impacts fragmentation avoidance.This patch changes all pageblocks within the high-order page being split
to the correct migratetype. Without the patch, allocation success rates
for hugepages under stress were about 59% of physical memory on x86-64.
With the patch applied, this goes up to 65%.Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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> -
By the time PG_mlocked is cleared in the page freeing path, nobody else is
looking at our page->flags anymore.It is thus safe to make the test-and-clear non-atomic and thereby removing
an unnecessary and expensive operation from a hotpath.Signed-off-by: Johannes Weiner
Reviewed-by: Christoph Lameter
Reviewed-by: KOSAKI Motohiro
Cc: Christoph Lameter
Cc: Mel Gorman
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__get_free_pages() with __GFP_HIGHMEM is not safe because the return
address cannot represent a highmem page. get_zeroed_page() already has
such a debug checking.Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the system is running a heavy load of processes then concurrent reclaim
can isolate a large number of pages from the LRU. /proc/vmstat and the
output generated for an OOM do not show how many pages were isolated.This has been observed during process fork bomb testing (mstctl11 in LTP).
This patch shows the information about isolated pages.
Reproduced via:
-----------------------
% ./hackbench 140 process 1000
=> OOM occuractive_anon:146 inactive_anon:0 isolated_anon:49245
active_file:79 inactive_file:18 isolated_file:113
unevictable:0 dirty:0 writeback:0 unstable:0 buffer:39
free:370 slab_reclaimable:309 slab_unreclaimable:5492
mapped:53 shmem:15 pagetables:28140 bounce:0Signed-off-by: KOSAKI Motohiro
Acked-by: Rik van Riel
Acked-by: Wu Fengguang
Reviewed-by: Minchan Kim
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It is possible for the oom killer to select current as the task to kill.
When this happens, alloc_flags needs to be updated accordingly to set
ALLOC_NO_WATERMARKS so the subsequent allocation attempt may use memory
reserves as the result of its thread having TIF_MEMDIE set if the
allocation is not __GFP_NOMEMALLOC.Acked-by: Mel Gorman
Signed-off-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Recently we encountered OOM problems due to memory use of the GEM cache.
Generally a large amuont of Shmem/Tmpfs pages tend to create a memory
shortage problem.We often use the following calculation to determine the amount of shmem
pages:shmem = NR_ACTIVE_ANON + NR_INACTIVE_ANON - NR_ANON_PAGES
however the expression does not consider isolated and mlocked pages.
This patch adds explicit accounting for pages used by shmem and tmpfs.
Signed-off-by: KOSAKI Motohiro
Acked-by: Rik van Riel
Reviewed-by: Christoph Lameter
Acked-by: Wu Fengguang
Cc: David Rientjes
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The amount of memory allocated to kernel stacks can become significant and
cause OOM conditions. However, we do not display the amount of memory
consumed by stacks.Add code to display the amount of memory used for stacks in /proc/meminfo.
Signed-off-by: KOSAKI Motohiro
Reviewed-by: Christoph Lameter
Reviewed-by: Minchan Kim
Reviewed-by: Rik van Riel
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It is often useful to know the statistics for all pages that are handled
like page cache pages when looking at OOM log output.Therefore show_free_areas() should also display buffer cache statistics.
Signed-off-by: KOSAKI Motohiro
Acked-by: Wu Fengguang
Reviewed-by: Rik van Riel
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
show_free_areas() displays only a limited amount of zone counters. This
patch includes additional counters in the display to allow easier
debugging. This may be especially useful if an OOM is due to running out
of DMA memory.Signed-off-by: KOSAKI Motohiro
Reviewed-by: Christoph Lameter
Acked-by: Wu Fengguang
Reviewed-by: Minchan Kim
Reviewed-by: Rik van Riel
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If an OOM happens, we really want to know the number of remaining
reclaimable pages. So the reclaimable slab and unreclaimable slab fields
should not be combined for display.Signed-off-by: KOSAKI Motohiro
Reviewed-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Ummark function as having kernel-doc notation, fixing the kernel-doc
warning.Warning(mm/page_alloc.c:4519): No description found for parameter 'zone'
Signed-off-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Pages on movable zone have two types, MIGRATE_MOVABLE and MIGRATE_RESERVE,
both them can be movable, because only movable memory allocation can get
pages from movable zone. This makes pages in movable zone always be able
to migrate.Signed-off-by: Shaohua Li
Cc: Mel Gorman
Cc: Christoph Lameter
Cc: Yakui Zhao
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Pages marked as isolated should not be allocated again. If such pages
reside in pcp list, they can be allocated too, so there is a ping-pong
memory offline frees some pages to pcp list and the pages get allocated
and then memory offline frees them again, this loop will happen again and
again.This should have no impact in normal code path, because in normal code
path, pages in pcp list aren't isolated, and below loop will break in the
first entry.Signed-off-by: Shaohua Li
Cc: Mel Gorman
Cc: Christoph Lameter
Cc: Yakui Zhao
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
