Re: [PATCH v2 8/8] mm: Centralize & improve oom reporting in show_mem.c
From: Michal Hocko <mhocko@suse.com>
Date: 2022-04-26 07:40:37
Also in:
linux-clk, linux-fsdevel, linux-mm, linux-tegra, lkml
On Tue 26-04-22 03:26:12, Kent Overstreet wrote: [...]
Anyways, the reason I think this allocation is fine is it's GFP_NOWAIT and it's completely fine if it fails - all we lose is some diagnostics, and also it's released right away.
I think you are still missing the PF_MEMALLOC point. Please have a look how this leads to no reclaim recursion so GFP_NOWAIT has no meaning when you are allocating from PF_MEMALLOC context (which the oom killer and any reclaim path is). Also have a look at how __gfp_pfmemalloc_flags makes the allocation request from that context ALLOC_NO_WATERMARKS. See? -- Michal Hocko SUSE Labs