Re: [PATCH 0/3] OOM detection rework v4

From: Michal Hocko
Date: Mon Feb 15 2016 - 15:06:27 EST


On Sun 07-02-16 13:09:33, Tetsuo Handa wrote:
[...]
> FYI, I again hit unexpected OOM-killer during genxref on linux-4.5-rc2 source.
> I think current patchset is too fragile to merge.
> ----------------------------------------
> [ 3101.626995] smbd invoked oom-killer: gfp_mask=0x27000c0(GFP_KERNEL_ACCOUNT|__GFP_NOTRACK), order=2, oom_score_adj=0
> [ 3101.629148] smbd cpuset=/ mems_allowed=0
[...]
> [ 3101.705887] Node 0 DMA: 75*4kB (UME) 69*8kB (UME) 43*16kB (UM) 23*32kB (UME) 8*64kB (UM) 4*128kB (UME) 2*256kB (UM) 0*512kB 1*1024kB (U) 1*2048kB (M) 0*4096kB = 6884kB
> [ 3101.710581] Node 0 DMA32: 4513*4kB (UME) 15*8kB (U) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 18172kB

How come this is an unexpected OOM? There is clearly no order-2+ page
available for the allocation request.

> > Something like the following:
> Yes, I do think we need something like it.

Was the patch applied?

--
Michal Hocko
SUSE Labs