linux-kernel - Re: [PATCH 1/2] f2fs: use vmalloc instead of kvmalloc in .init_{,de}compress

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]

Message-ID: <ba2bc9bf-7cec-4871-b603-8130c84fc917@kernel.org>
Date: Tue, 13 May 2025 14:34:25 +0800
From: Chao Yu <chao@...nel.org>
To: Christoph Hellwig <hch@...radead.org>
Cc: chao@...nel.org, jaegeuk@...nel.org,
 linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
 linux-mm@...ck.org
Subject: Re: [PATCH 1/2] f2fs: use vmalloc instead of kvmalloc in
 .init_{,de}compress_ctx

On 5/13/25 14:01, Christoph Hellwig wrote:
> On Tue, May 13, 2025 at 01:57:20PM +0800, Chao Yu wrote:
>> .init_{,de}compress_ctx uses kvmalloc() to alloc memory, it will try
>> to allocate physically continuous page first, it may cause more memory
>> allocation pressure, let's use vmalloc instead to mitigate it.
> 
> Shouldn't this be handled in kvmalloc instead of working around it in
> callers?

kvmalloc() will allocate physically continuous page first, so it may race
w/ other physically continuous page allocator who uses kmalloc(), in
scenario of there are few physically continuous pages.

Thanks,