On Monday 21 September 2009 10:58:44 Mel Gorman wrote:

On Sat, Sep 19, 2009 at 03:25:32PM +0200, Bartlomiej Zolnierkiewicz wrote:

quoted

On Wednesday 02 September 2009 20:26:17 Bartlomiej Zolnierkiewicz wrote:

quoted

On Wednesday 02 September 2009 20:02:14 Luis R. Rodriguez wrote:

quoted

On Wed, Sep 2, 2009 at 10:48 AM, Bartlomiej
Zolnierkiewicz[off-list ref] wrote:

quoted

On Sunday 30 August 2009 14:37:42 Bartlomiej Zolnierkiewicz wrote:

quoted

On Friday 28 August 2009 05:42:31 Zhu Yi wrote:

quoted

Bartlomiej Zolnierkiewicz reported an atomic order-6 allocation failure
for ipw2200 firmware loading in kernel 2.6.30. High order allocation is

s/2.6.30/2.6.31-rc6/

The issue has always been there but it was some recent change that
explicitly triggered the allocation failures (after 2.6.31-rc1).

ipw2200 fix works fine but yesterday I got the following error while mounting
ext4 filesystem (mb_history is optional so the mount succeeded):

OK so the mount succeeded.

quoted

EXT4-fs (dm-2): barriers enabled
kjournald2 starting: pid 3137, dev dm-2:8, commit interval 5 seconds
EXT4-fs (dm-2): internal journal on dm-2:8
EXT4-fs (dm-2): delayed allocation enabled
EXT4-fs: file extents enabled
mount: page allocation failure. order:5, mode:0xc0d0
Pid: 3136, comm: mount Not tainted 2.6.31-rc8-00015-gadda766-dirty #78
Call Trace:
 [<c0394de3>] ? printk+0xf/0x14
 [<c016a693>] __alloc_pages_nodemask+0x400/0x442
 [<c016a71b>] __get_free_pages+0xf/0x32
 [<c01865cf>] __kmalloc+0x28/0xfa
 [<c023d96f>] ? __spin_lock_init+0x28/0x4d
 [<c01f529d>] ext4_mb_init+0x392/0x460
 [<c01e99d2>] ext4_fill_super+0x1b96/0x2012
 [<c0239bc8>] ? snprintf+0x15/0x17
 [<c01c0b26>] ? disk_name+0x24/0x69
 [<c018ba63>] get_sb_bdev+0xda/0x117
 [<c01e6711>] ext4_get_sb+0x13/0x15
 [<c01e7e3c>] ? ext4_fill_super+0x0/0x2012
 [<c018ad2d>] vfs_kern_mount+0x3b/0x76
 [<c018adad>] do_kern_mount+0x33/0xbd
 [<c019d0af>] do_mount+0x660/0x6b8
 [<c016a71b>] ? __get_free_pages+0xf/0x32
 [<c019d168>] sys_mount+0x61/0x99
 [<c0102908>] sysenter_do_call+0x12/0x36
Mem-Info:
DMA per-cpu:
CPU    0: hi:    0, btch:   1 usd:   0
Normal per-cpu:
CPU    0: hi:  186, btch:  31 usd:   0
Active_anon:25471 active_file:22802 inactive_anon:25812
 inactive_file:33619 unevictable:2 dirty:2452 writeback:135 unstable:0
 free:4346 slab:4308 mapped:26038 pagetables:912 bounce:0
DMA free:2060kB min:84kB low:104kB high:124kB active_anon:1660kB inactive_anon:1848kB active_file:144kB inactive_file:868kB unevictable:0kB present:15788kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 489 489
Normal free:15324kB min:2788kB low:3484kB high:4180kB active_anon:100224kB inactive_anon:101400kB active_file:91064kB inactive_file:133608kB unevictable:8kB present:501392kB pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 1*4kB 1*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 1*2048kB 0*4096kB = 2060kB
Normal: 1283*4kB 648*8kB 159*16kB 53*32kB 10*64kB 1*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 15324kB
57947 total pagecache pages
878 pages in swap cache
Swap cache stats: add 920, delete 42, find 11/11
Free swap  = 1016436kB
Total swap = 1020116kB
131056 pages RAM
4233 pages reserved
90573 pages shared
77286 pages non-shared
EXT4-fs: mballoc enabled
EXT4-fs (dm-2): mounted filesystem with ordered data mode

Thus it seems like the original bug is still there and any ideas how to
debug the problem further are appreciated..

The complete dmesg and kernel config are here:

http://www.kernel.org/pub/linux/kernel/people/bart/ext4-paf.dmesg
http://www.kernel.org/pub/linux/kernel/people/bart/ext4-paf.config

This looks very similar to the kmemleak ext4 reports upon a mount. If
it is the same issue, which from the trace it seems it is, then this
is due to an extra kmalloc() allocation and this apparently will not
get fixed on 2.6.31 due to the closeness of the merge window and the
non-criticalness this issue has been deemed.

A patch fix is part of the ext4-patchqueue
http://repo.or.cz/w/ext4-patch-queue.git

Thanks for the pointer but the page allocation failures that I hit seem
to be caused by the memory management itself and the ext4 issue fixed by:

http://repo.or.cz/w/ext4-patch-queue.git?a=blob;f=memory-leak-fix-ext4_group_info-allocation;h=c919fff34e70ec85f96d1833f9ce460c451000de;hb=HEAD

is a different problem (unrelated to this one).

Here is another data point.

This time it is an order-6 page allocation failure for rt2870sta
(w/ upcoming driver changes) and Linus' tree from few days ago..

It's another high-order atomic allocation which is difficult to grant.
I didn't look closely, but is this the same type of thing - large allocation
failure during firmware loading? If so, is this during resume or is the
device being reloaded for some other reason?

Just modprobing the driver on a system running for some time.

I suspect that there are going to be a few of these bugs cropping up
every so often where network devices are assuming large atomic
allocations will succeed because the "only time they happen" is during
boot but these days are happening at runtime for other reasons.

I wouldn't go so far as calling a normal order-6 (256kB) allocation on
512MB machine with 1024MB swap a bug.  Moreover such failures just never
happened before 2.6.31-rc1.

I don't know why people don't see it but for me it has a memory management
regression and reliability issue written all over it.

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