From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Subject: Re: [PATCH 07/19] quota: make per-sb hash array Date: Thu, 28 Oct 2010 14:58:28 +0400 Message-ID: <87aalybn3f.fsf@dmon-lap.sw.ru> References: <1287768904-27810-1-git-send-email-dmonakhov@openvz.org> <1287768904-27810-8-git-send-email-dmonakhov@openvz.org> <20101027193109.GH19804@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, hch@infradead.org To: Al Viro Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:65519 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758158Ab0J1K6f (ORCPT ); Thu, 28 Oct 2010 06:58:35 -0400 Received: by eye27 with SMTP id 27so1361120eye.19 for ; Thu, 28 Oct 2010 03:58:34 -0700 (PDT) In-Reply-To: <20101027193109.GH19804@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, 27 Oct 2010 20:31:09 +0100, Al Viro wrote: > On Fri, Oct 22, 2010 at 09:34:52PM +0400, Dmitry Monakhov wrote: > > From: Dmitry Monakhov > > > > Currently quota_hash[] is global, which is bad for scalability. > > Also is is the last user of global dq_list_lock. > > It is reasonable to introduce dedicated hash for each super_block > > which use quota. > > > > per-sb hash will be allocated only when necessary (on first quota_on()) > > Protected by per-sb dq_list_lock. > > Ugh... Why not a common hash with per-chain spinlock? We'll waste less > memory on those than on hash chain heads even for a couple of superblocks > and unless you've got boxen with more (quota'd) superblocks than hash chains, > you'll get less contention... Ok, i'll use "kernel: add bl_list" per-backet list implementation from nick@. > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html