From: Lukas Czerner Subject: Re: [PATCHSET v2] ext4: removal of alloc_sem locks from block allocation paths Date: Tue, 10 May 2011 15:48:58 +0200 (CEST) Message-ID: References: <1300985893-4371-1-git-send-email-amir73il@users.sourceforge.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: tytso@mit.edu, linux-ext4@vger.kernel.org To: amir73il@users.sourceforge.net Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23597 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754735Ab1EJNtM (ORCPT ); Tue, 10 May 2011 09:49:12 -0400 In-Reply-To: <1300985893-4371-1-git-send-email-amir73il@users.sourceforge.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, 24 Mar 2011, amir73il@users.sourceforge.net wrote: > The purpose of this patch set is the removal of grp->alloc_sem locks > from block allocation paths. > > The resulting code is cleaner and should perform better in concurrent > allocating tasks workloads. Hi Amir, Do you have any performance numbers indicating performance improvement in concurrent allocations ? The only point where I can see taking write semaphore is in filesystem resize code. Or am I missing something ? Thanks! -Lukas > > I ran several xfstests runs with these patches (4K and 1K block size). > I tried several online resizes and verifyed that both in-core and on-disk > group counters are correct. > > v2->v1: > - fix silly bug in patch 4/5 that triggers BUG_ON(incore == NULL) > - replace get_undo_access() with get_write_access() > - ran xfstests with block size 1K (where 2 groups share a buddy page) > > [PATCH v2 1/5] ext4: move ext4_add_groupblocks() to mballoc.c > [PATCH v2 2/5] ext4: implement ext4_add_groupblocks() by freeing blocks > [PATCH v2 3/5] ext4: synchronize ext4_mb_init_group() with buddy page lock > [PATCH v2 4/5] ext4: teach ext4_mb_init_cache() to skip uptodate buddy caches > [PATCH v2 5/5] ext4: remove alloc_semp > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > --