Re: Bcache still unstable for me (memory problems)

[Marc MERLIN <marc@merlins.org>]

On Thu, Mar 10, 2016 at 07:29:58AM -0800, Marc MERLIN wrote:
> On Wed, Mar 09, 2016 at 06:15:16PM -0800, Marc MERLIN wrote:
> > On Thu, Mar 10, 2016 at 01:34:56AM +0000, Eric Wheeler wrote:
> > > Hi Richard, Marc,
> > > 
> > > >>> [290623.673871] bcache-register: page allocation failure: order:7, mode:0x24080c0
> > > 
> > > Do you still have the backtraces that show the function call stack for 
> > > errors that look like this?
> > > 	%s: page allocation failure: order:%d, mode:0x%x 
> > > 
> > > Please send as many relevant OOM failure traces that you can.  I would 
> > > like to see which memory allocation(s) are failing and if they are always 
> > > the same stack trace.
> >  
> > It's the same one I already sent you, just from syslog instead of serial
> > console (I was looking for other relevant cronjobs or errors per your
> > request)
>  
> Ok, here's a new one with your patches installed. Good thing is that
> kernel didn't crash. But adding caching device still failed.

Mmmh, so I just stopped a bcache, made another one with make-bcache, and my machine died.

Sadly, the actual crash wasn't captured due to my serial console server having failed.
I got this below from remote syslog, the real crash happened later and wasn't logged.

Hope this helps.

bcache-register: page allocation failure: order:7, mode:0x24080c0
CPU: 0 PID: 13517 Comm: bcache-register Not tainted 4.4.2-amd64-i915-volpreempt-sysrq-20160214bc5 #8
Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
 0000000000000000 ffff88037cb4fb00 ffffffff8134ae4a 0000000000000001
 ffff88037cb4fb98 ffffffff81124b00 024080c07cb4fc3c 024080c000000040
 0000000700000001 0000000000000007 0000000000000007 0000000000000040
Call Trace:
 [<ffffffff8134ae4a>] dump_stack+0x44/0x55
 [<ffffffff81124b00>] warn_alloc_failed+0x114/0x12c
 [<ffffffff81127502>] __alloc_pages_nodemask+0x7cb/0x84c
 [<ffffffff8107dfca>] ? try_to_wake_up+0x1d9/0x1eb
 [<ffffffff8115f721>] alloc_pages_current+0xa9/0xcd
 [<ffffffff811237c8>] __get_free_pages+0xe/0x3c
 [<ffffffffc059530b>] bch_cache_set_alloc+0x3c7/0x479 [bcache]
 [<ffffffffc05965ea>] register_bcache+0x122d/0x143c [bcache]
 [<ffffffff8134c893>] kobj_attr_store+0x10/0x1a
 [<ffffffff811dfa29>] sysfs_kf_write+0x39/0x3b
 [<ffffffff811df32b>] kernfs_fop_write+0xed/0x130
 [<ffffffff8117d9c7>] __vfs_write+0x26/0xa5
 [<ffffffff810b29b3>] ? current_kernel_time64+0x10/0x36
 [<ffffffff812d609a>] ? security_file_permission+0x3b/0x42
 [<ffffffff81091634>] ? percpu_down_read+0x12/0x41
 [<ffffffff8117fbab>] ? __sb_start_write+0x2b/0x48
 [<ffffffff8117e032>] vfs_write+0x9d/0xe8
 [<ffffffff8117e807>] SyS_write+0x4d/0x78
 [<ffffffff810039c3>] do_fast_syscall_32+0xb3/0xf3
 [<ffffffff816e3e72>] sysenter_flags_fixed+0x8/0x12
Mem-Info:
active_anon:468787 inactive_anon:167077 isolated_anon:0
 active_file:1380425 inactive_file:1192252 isolated_file:0
 unevictable:1474 dirty:39397 writeback:3372 unstable:0
 slab_reclaimable:164804 slab_unreclaimable:70389
 mapped:416857 shmem:409963 pagetables:4551 bounce:0
 free:302751 free_pcp:1140 free_cma:384
Node 0 DMA free:15892kB min:256kB low:320kB high:384kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB ilowmem_reserve[]: 0 3201 15736 15736
Node 0 DMA32 free:554388kB min:53336kB low:66668kB high:80004kB active_anon:185968kB inactive_anon:196384kB active_file:1429216kB inactive_flowmem_reserve[]: 0 0 12535 12535
Node 0 Normal free:651784kB min:208544kB low:260680kB high:312816kB active_anon:1688260kB inactive_anon:471920kB active_file:4092556kB inact lowmem_reserve[]: 0 0 0 0
Node 0 DMA: 1*4kB (U) 0*8kB 1*16kB (U) 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15892kB
Node 0 DMA32: 20169*4kB (UME) 59104*8kB (UME) 46*16kB (UM) 4*32kB (UM) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 554372kB
Node 0 Normal: 58345*4kB (UMEC) 40698*8kB (UMEC) 4028*16kB (UMEC) 430*32kB (UMEC) 160*64kB (UM) 35*128kB (UM) 10*256kB (M) 0*512kB 0*1024kB 
Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
2991157 total pagecache pages
7348 pages in swap cache
Swap cache stats: add 516663, delete 509315, find 10110495/10164991
Free swap  = 14686944kB
Total swap = 15616764kB
4118751 pages RAM
0 pages HighMem/MovableOnly
85016 pages reserved
4096 pages cma reserved
0 pages hwpoisoned
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/