The patch titled
     vfs: avoid large kmalloc()s for the fdtable
has been added to the -mm tree.  Its filename is
     vfs-avoid-large-kmallocs-for-the-fdtable.patch

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*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: vfs: avoid large kmalloc()s for the fdtable
From: Andrew Morton <[email protected]>

Azurit reports large increases in system time after 2.6.36 when running
Apache.  It was bisected down to a892e2d7dcdfa6c76e6 ("vfs: use kmalloc()
to allocate fdmem if possible").

That patch caused the vfs to use kmalloc() for very large allocations and
this is causing excessive work (and presumably excessive reclaim) within
the page allocator.

Fix it by falling back to vmalloc() earlier - when the allocation attempt
would have been considered "costly" by reclaim.

Reported-by: azurIt <[email protected]>
Cc: Changli Gao <[email protected]>
Cc: Americo Wang <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 fs/file.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff -puN fs/file.c~a fs/file.c
--- a/fs/file.c~a
+++ a/fs/file.c
@@ -39,14 +39,17 @@ int sysctl_nr_open_max = 1024 * 1024; /*
  */
 static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);
 
-static inline void *alloc_fdmem(unsigned int size)
+static void *alloc_fdmem(unsigned int size)
 {
-       void *data;
-
-       data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN);
-       if (data != NULL)
-               return data;
-
+       /*
+        * Very large allocations can stress page reclaim, so fall back to
+        * vmalloc() if the allocation size will be considered "large" by the 
VM.
+        */
+       if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER) {
+               void *data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN);
+               if (data != NULL)
+                       return data;
+       }
        return vmalloc(size);
 }
 
_

Patches currently in -mm which might be from [email protected] are

origin.patch
linux-next.patch
linux-next-git-rejects.patch
next-remove-localversion.patch
i-need-old-gcc.patch
arch-alpha-kernel-systblss-remove-debug-check.patch
drivers-i2c-busses-i2c-designware-corec-needs-delayh.patch
fs-partitions-ldmc-fix-oops-caused-by-corrupted-partition-table-checkpatch-fixes.patch
mm-add-vm-counters-for-transparent-hugepages.patch
mm-thp-use-conventional-format-for-boolean-attributes-fix.patch
vfs-avoid-large-kmallocs-for-the-fdtable.patch
drivers-scsi-mpt2sas-mpt2sas_ctlc-fix-unbounded-copy_to_user.patch
arch-x86-include-asm-delayh-fix-udelay-and-ndelay-for-8-bit-args.patch
drivers-gpu-drm-radeon-atomc-fix-warning.patch
leds-route-kbd-leds-through-the-generic-leds-layer.patch
backlight-add-backlight-type-fix.patch
backlight-add-backlight-type-fix-fix.patch
drivers-video-backlight-adp5520_blc-check-strict_strtoul-return-value-fix.patch
drivers-message-fusion-mptsasc-fix-warning.patch
osst-wrong-index-used-in-inner-loop-checkpatch-fixes.patch
drbd-fix-warning.patch
mm.patch
mm-nommu-sort-mm-mmap-list-properly-fix.patch
mm-per-node-vmstat-show-proper-vmstats-fix.patch
mm-mem-hotplug-update-pcp-stat_threshold-when-memory-hotplug-occur-fix.patch
frv-duplicate-output_buffer-of-e03-checkpatch-fixes.patch
hpet-factor-timer-allocate-from-open.patch
arch-alpha-include-asm-ioh-s-extern-inline-static-inline.patch
init-calibratec-fix-for-critical-bogomips-intermittent-calculation-failure-checkpatch-fixes.patch
init-calibratec-fix-for-critical-bogomips-intermittent-calculation-failure-fix.patch
lru_cache-use-correct-type-in-sizeof-for-allocation-fix.patch
lib-genpoolc-document-return-values-fix-gen_pool_add_virt-return-value.patch
lib-hexdumpc-make-hex2bin-return-the-updated-src-address.patch
fs-binfmt_miscc-use-kernels-hex_to_bin-method-fix.patch
fs-binfmt_miscc-use-kernels-hex_to_bin-method-fix-fix.patch
fs-ncpfs-inodec-suppress-used-uninitialised-warning.patch
drivers-tty-vt-vt_ioctlc-repair-insane-expression.patch
drivers-rtc-rtc-mrstc-use-release_mem_region-after-request_mem_region-fix.patch
rtc-driver-for-pt7c4338-chip-checkpatch-fixes.patch
rtc-driver-for-pt7c4338-chip-fix.patch
documentation-accounting-getdelaysc-handle-sendto-failures.patch
mm-move-enum-vm_event_item-into-a-standalone-header-file.patch
add-the-pagefault-count-into-memcg-stats-fix.patch
dev-kmsg-properly-support-writev-to-avoid-interleaved-printk-lines-fix.patch
fs-partitions-efic-corrupted-guid-partition-tables-can-cause-kernel-oops-fix.patch
scatterlist-new-helper-functions.patch
scatterlist-new-helper-functions-update-fix.patch
kexec-remove-kmsg_dump_kexec-fix.patch
journal_add_journal_head-debug.patch
mutex-subsystem-synchro-test-module-fix.patch
slab-leaks3-default-y.patch
put_bh-debug.patch
memblock-add-input-size-checking-to-memblock_find_region.patch
memblock-add-input-size-checking-to-memblock_find_region-fix.patch

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