From: Michal Hocko <mhocko@suse.com>
To: Yu Zhao <yuzhao@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Link Lin <linkl@google.com>
Subject: Re: [PATCH mm-unstable v1] mm/page_alloc: try not to overestimate free highatomic
Date: Mon, 21 Oct 2024 10:13:33 +0200 [thread overview]
Message-ID: <ZxYNLb0CiZyw31_q@tiehlicka> (raw)
In-Reply-To: <20241020051315.356103-1-yuzhao@google.com>
On Sat 19-10-24 23:13:15, Yu Zhao wrote:
> OOM kills due to vastly overestimated free highatomic reserves were
> observed:
>
> ... invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0 ...
> Node 0 Normal free:1482936kB boost:0kB min:410416kB low:739404kB high:1068392kB reserved_highatomic:1073152KB ...
> Node 0 Normal: 1292*4kB (ME) 1920*8kB (E) 383*16kB (UE) 220*32kB (ME) 340*64kB (E) 2155*128kB (UE) 3243*256kB (UE) 615*512kB (U) 1*1024kB (M) 0*2048kB 0*4096kB = 1477408kB
>
> The second line above shows that the OOM kill was due to the following
> condition:
>
> free (1482936kB) - reserved_highatomic (1073152kB) = 409784KB < min (410416kB)
>
> And the third line shows there were no free pages in any
> MIGRATE_HIGHATOMIC pageblocks, which otherwise would show up as type
> 'H'. Therefore __zone_watermark_unusable_free() overestimated free
> highatomic reserves. IOW, it underestimated the usable free memory by
> over 1GB, which resulted in the unnecessary OOM kill.
Why doesn't unreserve_highatomic_pageblock deal with this situation?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2024-10-21 8:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-20 5:13 Yu Zhao
2024-10-21 8:13 ` Michal Hocko [this message]
2024-10-21 17:10 ` Yu Zhao
2024-10-21 17:25 ` Michal Hocko
2024-10-21 17:47 ` Yu Zhao
2024-10-22 10:53 ` Vlastimil Babka
2024-10-23 6:36 ` Yu Zhao
2024-10-23 7:34 ` Vlastimil Babka
2024-10-23 9:25 ` Matt Fleming
2024-10-23 9:44 ` Vlastimil Babka
2024-10-24 4:35 ` Yu Zhao
2024-10-24 8:16 ` Vlastimil Babka
2024-10-24 21:15 ` Yu Zhao
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