From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1543CC4338F for ; Fri, 30 Jul 2021 14:40:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 022FE60FE7 for ; Fri, 30 Jul 2021 14:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239339AbhG3OkN (ORCPT ); Fri, 30 Jul 2021 10:40:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239286AbhG3OkN (ORCPT ); Fri, 30 Jul 2021 10:40:13 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76BEFC061765 for ; Fri, 30 Jul 2021 07:40:07 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id nh14so3729672pjb.2 for ; Fri, 30 Jul 2021 07:40:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=references:user-agent:from:to:cc:subject:in-reply-to:date :message-id:mime-version; bh=kc+LsMPr36uEqQi30YEowzrG+MYNybY3yXsORHPsefk=; b=HRhGnBU8YKjc2u3D/D5GfCwIzk37V53EoG6uPrJy2seCLe0mgZ89Vr1CiU5Pi7rOzp fTadMD/CPxod+MushAY0lb3PScNZ3rX2d8SH7Pm9C3qWdCIopkVgcSTCZVrcIiTewr31 hilqSnmcUR6iLCpylMFzExZ52QF8ROivbqD4hmpvqitt0206y4EfpaksgiWQAhMGLsv2 UkLrwFOZjYkd6tDmv3HFu+9Vr1FTTiQzQmtcQYhXLKKDuTrMNUT85C+1j5r+OPCgC+Bd BqVw0rMsPKHf/Hb1lNaoLCZWYj5m9Bu7+fpFb7SYfqHcMXfGDi7EDA0khVQOl0mQG4JP zxfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version; bh=kc+LsMPr36uEqQi30YEowzrG+MYNybY3yXsORHPsefk=; b=okuSjf8tjhxRV8hFldarw9Fku2V/Ocqrc7xtTFCy1UwGqh3j6j/rgf89JhK++lSKJc hIxAjP43915eDBEvRmWHiDQQSN64ljb5XIdG89Mhb50oCkbSvMFgAf/OtMYBJM283aNO T8Oh00GkEoB/s+vpK0+J8V1QKFLK+Nl7cqRJbULW5vRv6XXZYpHIezV7/LiMneAfAP3r G9QUj/nyv/tPuFcGDIhrjQB8b50sVoA4WksIuXUphTtFs38lxxoEl3C2jp8Xma8vv5pC kH9PGWVwZEh7qpy0+6M54Dg09Kr0MgEkLhUuONM2Es/fdsLDjOYAFV6o1x0eeCrMpYBd uyUg== X-Gm-Message-State: AOAM531c3HeZ8a1k7pJ5oZhHPSjRPYRENEYxZWPVPE8fOpy/KjYpw38x J2C/oErqppWHLLHrS/l5bUTuhKdz+jxdqQ== X-Google-Smtp-Source: ABdhPJz4ZZUAD/TofNVBCl2inws5SnpHZCx+RFi/ffVV9oWD9VDDvz59nBfQddnuaRuvg4D/TAucOQ== X-Received: by 2002:a17:90a:5d8a:: with SMTP id t10mr3594260pji.6.1627656006826; Fri, 30 Jul 2021 07:40:06 -0700 (PDT) Received: from garuda ([122.171.174.228]) by smtp.gmail.com with ESMTPSA id t17sm2579047pfg.93.2021.07.30.07.40.05 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 30 Jul 2021 07:40:06 -0700 (PDT) References: <20210727062053.11129-1-allison.henderson@oracle.com> <20210727062053.11129-11-allison.henderson@oracle.com> User-agent: mu4e 1.0; emacs 26.1 From: Chandan Babu R To: Allison Henderson Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH v22 10/16] RFC xfs: Skip flip flags for delayed attrs In-reply-to: <20210727062053.11129-11-allison.henderson@oracle.com> Date: Fri, 30 Jul 2021 20:10:04 +0530 Message-ID: <87tukb986z.fsf@garuda> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On 27 Jul 2021 at 11:50, Allison Henderson wrote: > This is a clean up patch that skips the flip flag logic for delayed attr > renames. Since the log replay keeps the inode locked, we do not need to > worry about race windows with attr lookups. So we can skip over > flipping the flag and the extra transaction roll for it > > RFC: In the last review, folks asked for some performance analysis, so I > did a few perf captures with and with out this patch. What I found was > that there wasnt very much difference at all between having the patch or > not having it. Of the time we do spend in the affected code, the > percentage is small. Most of the time we spend about %0.03 of the time > in this function, with or with out the patch. Occasionally we get a > 0.02%, though not often. So I think this starts to challenge needing > this patch at all. This patch was requested some number of reviews ago, > be perhaps in light of the findings, it may no longer be of interest. > > 0.03% 0.00% fsstress [xfs] [k] xfs_attr_set_iter > > Keep it or drop it? > Apart from the issues pointed out by Darrick, the remaining changes seem to be fine. > Signed-off-by: Allison Henderson > Reviewed-by: Darrick J. Wong > --- > fs/xfs/libxfs/xfs_attr.c | 51 +++++++++++++++++++++++++------------------ > fs/xfs/libxfs/xfs_attr_leaf.c | 3 ++- > 2 files changed, 32 insertions(+), 22 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index 11d8081..eee219c6 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c > @@ -355,6 +355,7 @@ xfs_attr_set_iter( > struct xfs_inode *dp = args->dp; > struct xfs_buf *bp = NULL; > int forkoff, error = 0; > + struct xfs_mount *mp = args->dp->i_mount; > > /* State machine switch */ > switch (dac->dela_state) { > @@ -476,16 +477,21 @@ xfs_attr_set_iter( > * In a separate transaction, set the incomplete flag on the > * "old" attr and clear the incomplete flag on the "new" attr. > */ > - error = xfs_attr3_leaf_flipflags(args); > - if (error) > - return error; > - /* > - * Commit the flag value change and start the next trans in > - * series. > - */ > - dac->dela_state = XFS_DAS_FLIP_LFLAG; > - trace_xfs_attr_set_iter_return(dac->dela_state, args->dp); > - return -EAGAIN; > + if (!xfs_hasdelattr(mp)) { > + error = xfs_attr3_leaf_flipflags(args); > + if (error) > + return error; > + /* > + * Commit the flag value change and start the next trans > + * in series. > + */ > + dac->dela_state = XFS_DAS_FLIP_LFLAG; > + trace_xfs_attr_set_iter_return(dac->dela_state, > + args->dp); > + return -EAGAIN; > + } > + > + /* fallthrough */ > case XFS_DAS_FLIP_LFLAG: > /* > * Dismantle the "old" attribute/value pair by removing a > @@ -587,17 +593,21 @@ xfs_attr_set_iter( > * In a separate transaction, set the incomplete flag on the > * "old" attr and clear the incomplete flag on the "new" attr. > */ > - error = xfs_attr3_leaf_flipflags(args); > - if (error) > - goto out; > - /* > - * Commit the flag value change and start the next trans in > - * series > - */ > - dac->dela_state = XFS_DAS_FLIP_NFLAG; > - trace_xfs_attr_set_iter_return(dac->dela_state, args->dp); > - return -EAGAIN; > + if (!xfs_hasdelattr(mp)) { > + error = xfs_attr3_leaf_flipflags(args); > + if (error) > + goto out; > + /* > + * Commit the flag value change and start the next trans > + * in series > + */ > + dac->dela_state = XFS_DAS_FLIP_NFLAG; > + trace_xfs_attr_set_iter_return(dac->dela_state, > + args->dp); > + return -EAGAIN; > + } > > + /* fallthrough */ > case XFS_DAS_FLIP_NFLAG: > /* > * Dismantle the "old" attribute/value pair by removing a > @@ -1241,7 +1251,6 @@ xfs_attr_node_addname_clear_incomplete( > * Re-find the "old" attribute entry after any split ops. The INCOMPLETE > * flag means that we will find the "old" attr, not the "new" one. > */ > - args->attr_filter |= XFS_ATTR_INCOMPLETE; > state = xfs_da_state_alloc(args); > state->inleaf = 0; > error = xfs_da3_node_lookup_int(state, &retval); > diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c > index b910bd2..a9116ee 100644 > --- a/fs/xfs/libxfs/xfs_attr_leaf.c > +++ b/fs/xfs/libxfs/xfs_attr_leaf.c > @@ -1482,7 +1482,8 @@ xfs_attr3_leaf_add_work( > if (tmp) > entry->flags |= XFS_ATTR_LOCAL; > if (args->op_flags & XFS_DA_OP_RENAME) { > - entry->flags |= XFS_ATTR_INCOMPLETE; > + if (!xfs_hasdelattr(mp)) > + entry->flags |= XFS_ATTR_INCOMPLETE; > if ((args->blkno2 == args->blkno) && > (args->index2 <= args->index)) { > args->index2++; -- chandan