linux-kernel - [PATCH 3/6] 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]

Date:	Thu, 27 Nov 2008 00:32:24 +0100
From:	Eric Dumazet <dada1@...mosbay.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	David Miller <davem@...emloft.net>,
	"Rafael J. Wysocki" <rjw@...k.pl>, linux-kernel@...r.kernel.org,
	kernel-testers@...r.kernel.org, Mike Galbraith <efault@....de>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Linux Netdev List <netdev@...r.kernel.org>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Christoph Hellwig <hch@...radead.org>
Subject: [PATCH 3/6] fs: Introduce a per_cpu last_ino allocator

new_inode() dirties a contended cache line to get inode numbers.

Solve this problem by providing to each cpu a per_cpu variable,
feeded by the shared last_ino, but once every 1024 allocations.

This reduce contention on the shared last_ino.

Note : last_ino_get() method must be called with preemption
disabled on SMP.


(socket8 bench result : no differences, but this is because inode_lock
cost is too heavy)

Signed-off-by: Eric Dumazet <dada1@...mosbay.com>
---
 fs/inode.c |   27 +++++++++++++++++++++++++--
 1 files changed, 25 insertions(+), 2 deletions(-)

View attachment "last_ino.patch" of type "text/plain" (1309 bytes)