linux-kernel - Re: [PATCH 15/18] fs: introduce a per-cpu last

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: <20101008095658.GA19804@ZenIV.linux.org.uk>
Date:	Fri, 8 Oct 2010 10:56:58 +0100
From:	Al Viro <viro@...IV.linux.org.uk>
To:	Dave Chinner <david@...morbit.com>
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 15/18] fs: introduce a per-cpu last_ino allocator

On Fri, Oct 08, 2010 at 04:21:29PM +1100, Dave Chinner wrote:
> From: Eric Dumazet <eric.dumazet@...il.com>
> 
> new_inode() dirties a contended cache line to get increasing
> inode numbers. This limits performance on workloads that cause
> significant parallel inode allocation.
> 
> Solve this problem by using a per_cpu variable fed by the shared
> last_ino in batches of 1024 allocations.  This reduces contention on
> the shared last_ino, and give same spreading ino numbers than before
> (i.e. same wraparound after 2^32 allocations).

FWIW, that one is begging to be split; what I mean is that there are
two classes of callers; ones that will set i_ino themselves anyway
and ones that really want i_ino invented.  Two functions?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/