linux-kernel - Re: kswapd0: page allocation failure: order:0, mode:0x820(GFP_ATOMIC), nodemask=(null),cpuset=/,mems

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Tue, 4 Jun 2024 13:44:58 +0200
From: Erhard Furtner <erhard_f@...lbox.org>
To: Yosry Ahmed <yosryahmed@...gle.com>
Cc: Yu Zhao <yuzhao@...gle.com>, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: kswapd0: page allocation failure: order:0,
 mode:0x820(GFP_ATOMIC), nodemask=(null),cpuset=/,mems_allowed=0 (Kernel
 v6.5.9, 32bit ppc)

On Mon, 3 Jun 2024 16:24:02 -0700
Yosry Ahmed <yosryahmed@...gle.com> wrote:

> Thanks for bisecting. Taking a look at the thread, it seems like you
> have a very limited area of memory to allocate kernel memory from. One
> possible reason why that commit can cause an issue is because we will
> have multiple instances of the zsmalloc slab caches 'zspage' and
> 'zs_handle', which may contribute to fragmentation in slab memory.
> 
> Do you have /proc/slabinfo from a good and a bad run by any chance?
> 
> Also, could you check if the attached patch helps? It makes sure that
> even when we use multiple zsmalloc zpools, we will use a single slab
> cache of each type.

Thanks for looking into this! I got you 'cat /proc/slabinfo' from a good HEAD, from a bad HEAD and from the bad HEAD + your patch applied.

Good was 6be3601517d90b728095d70c14f3a04b9adcb166, bad was b8cf32dc6e8c75b712cbf638e0fd210101c22f17 which I got both from my bisect.log. I got the slabinfo shortly after boot and a 2nd time shortly before the OOM or the kswapd0: page allocation failure happens. I terminated the workload (stress-ng --vm 2 --vm-bytes 1930M --verify -v) manually shortly before the 2 GiB RAM exhausted and got the slabinfo then.

The patch applied to git b8cf32dc6e8c75b712cbf638e0fd210101c22f17 unfortunately didn't make a difference, I got the kswapd0: page allocation failure nevertheless.

Regards,
Erhard

View attachment "slabinfo_patch-boot.txt" of type "text/plain" (23502 bytes)

View attachment "slabinfo_patch-be.txt" of type "text/plain" (23502 bytes)

View attachment "slabinfo_bad-boot.txt" of type "text/plain" (30136 bytes)

View attachment "slabinfo_good-boot.txt" of type "text/plain" (23502 bytes)

View attachment "slabinfo_bad-be.txt" of type "text/plain" (30136 bytes)

View attachment "slabinfo_good-be.txt" of type "text/plain" (23503 bytes)