linux-kernel - Re: [patch 1/6] fs: icache RCU free inodes

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 for Android: free password hash cracker in your pocket

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

Date:	Thu, 11 Nov 2010 20:48:38 -0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Nick Piggin <npiggin@...il.com>
Cc:	Nick Piggin <npiggin@...nel.dk>,
	Eric Dumazet <eric.dumazet@...il.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [patch 1/6] fs: icache RCU free inodes

On Thu, Nov 11, 2010 at 5:24 PM, Nick Piggin <npiggin@...il.com> wrote:
>
> So this is really not a "oh, maybe someone will see 10-20% slowdown", or even
> 1-2% slowdown.

You ignored my bigger issue: the _normal_ way - and the better way -
to handle these thingsis with SLAB_DESTROY_BY_RCU.

So what are the advantages of using the inferior approach?  I really
don't see why you push the whole "free the damn things individually"
approach. We've had experience with that, and it's resulted in long
RCU queues with memory being held up in queuing etc (hopefully we've
improved on the queuing issues with RCU itself, but..)

So the thing is, SLAB_DESTROY_BY_RCU is just the RightThing(tm). Why fight it?

                   Linus
--
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/