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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 F3962C2D0EA for ; Wed, 8 Apr 2020 11:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD5D820787 for ; Wed, 8 Apr 2020 11:43:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="duuxeGXp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728625AbgDHLnU (ORCPT ); Wed, 8 Apr 2020 07:43:20 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:26801 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728572AbgDHLnU (ORCPT ); Wed, 8 Apr 2020 07:43:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586346197; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VkIf2f7G4BzDdOB7aIAYxEq48cTU3D5XAAX5LlMyjcQ=; b=duuxeGXpMppmcwRnBReNJqqBvGLazKRxIgRzoZVgWaNnRQTw51QPb+GxfvoMZOH2ifqST+ l07o9Tz+H7HrSTDmNoiTdjdMTbFV8InO6gN4HhdzX2dT/Sax4tpuByMF1G0uaXaJSXTHVe pRHiFRileIJHa71dFul3DET16hH4nQU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-484-Ssxb08zjPAOtCUlmcx4UZQ-1; Wed, 08 Apr 2020 07:43:16 -0400 X-MC-Unique: Ssxb08zjPAOtCUlmcx4UZQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2A703800D50; Wed, 8 Apr 2020 11:43:15 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BF84E7E303; Wed, 8 Apr 2020 11:43:14 +0000 (UTC) Date: Wed, 8 Apr 2020 07:43:12 -0400 From: Brian Foster To: Allison Collins Cc: linux-xfs@vger.kernel.org Subject: Re: [RFC v6 PATCH 03/10] xfs: extra runtime reservation overhead for relog transactions Message-ID: <20200408114312.GA33192@bfoster> References: <20200406123632.20873-1-bfoster@redhat.com> <20200406123632.20873-4-bfoster@redhat.com> <24e8c67b-be11-cd04-81d1-8eeb1122f33e@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <24e8c67b-be11-cd04-81d1-8eeb1122f33e@oracle.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Apr 07, 2020 at 04:04:43PM -0700, Allison Collins wrote: > > > On 4/6/20 5:36 AM, Brian Foster wrote: > > Every transaction reservation includes runtime overhead on top of > > the reservation calculated in the struct xfs_trans_res. This > > overhead is required for things like the CIL context ticket, log > > headers, etc., that are stolen from individual transactions. Since > > reservation for the relog transaction is entirely contributed by > > regular transactions, this runtime reservation overhead must be > > contributed as well. This means that a transaction that relogs one > > or more items must include overhead for the current transaction as > > well as for the relog transaction. > > > > Define a new transaction flag to indicate that a transaction is > > relog enabled. Plumb this state down to the log ticket allocation > > and use it to bump the worst case overhead included in the > > transaction. The overhead will eventually be transferred to the > > relog system as needed for individual log items. > > > > Signed-off-by: Brian Foster > > --- > > fs/xfs/libxfs/xfs_shared.h | 1 + > > fs/xfs/xfs_log.c | 12 +++++++++--- > > fs/xfs/xfs_log.h | 3 ++- > > fs/xfs/xfs_log_cil.c | 2 +- > > fs/xfs/xfs_log_priv.h | 1 + > > fs/xfs/xfs_trans.c | 3 ++- > > 6 files changed, 16 insertions(+), 6 deletions(-) > > > > diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h > > index c45acbd3add9..1ede1e720a5c 100644 > > --- a/fs/xfs/libxfs/xfs_shared.h > > +++ b/fs/xfs/libxfs/xfs_shared.h > > @@ -65,6 +65,7 @@ void xfs_log_get_max_trans_res(struct xfs_mount *mp, > > #define XFS_TRANS_DQ_DIRTY 0x10 /* at least one dquot in trx dirty */ > > #define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */ > > #define XFS_TRANS_NO_WRITECOUNT 0x40 /* do not elevate SB writecount */ > > +#define XFS_TRANS_RELOG 0x80 /* requires extra relog overhead */ > > /* > > * LOWMODE is used by the allocator to activate the lowspace algorithm - when > > * free space is running low the extent allocator may choose to allocate an > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > > index d6b63490a78b..b55abde6c142 100644 > > --- a/fs/xfs/xfs_log.c > > +++ b/fs/xfs/xfs_log.c > > @@ -418,7 +418,8 @@ xfs_log_reserve( > > int cnt, > > struct xlog_ticket **ticp, > > uint8_t client, > > - bool permanent) > > + bool permanent, > > + bool relog) > > { > > struct xlog *log = mp->m_log; > > struct xlog_ticket *tic; > > @@ -433,7 +434,8 @@ xfs_log_reserve( > > XFS_STATS_INC(mp, xs_try_logspace); > > ASSERT(*ticp == NULL); > > - tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent, 0); > > + tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent, relog, > > + 0); > > *ticp = tic; > > xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt > > @@ -831,7 +833,7 @@ xlog_unmount_write( > > uint flags = XLOG_UNMOUNT_TRANS; > > int error; > > - error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0); > > + error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, false, false); > > if (error) > > goto out_err; > > @@ -3421,6 +3423,7 @@ xlog_ticket_alloc( > > int cnt, > > char client, > > bool permanent, > > + bool relog, > > xfs_km_flags_t alloc_flags) > I notice this routine already has a flag param. Wondering if it would make > sense to have a KM_RELOG flag instead of an extra bool param? It would just > be one less thing to pass around. Other than that, it seems straight > forward. > In the xlog_ticket_alloc() case, those are actually memory allocation flags (as opposed to transaction flags used in xfs_trans_alloc()). The former includes things like KM_NOFS, etc., that translate to GFP_* allocation flags. So I don't think it's appropriate to stash a transaction or ticket oriented flag there. I did halfway expect some feedback wrt to XFS_TRANS_RELOG because it technically could be buried in the reservation structure itself, similar to how permanent state is handled (though we'd still need to pass the boolean around a bit). I opted to introduce XFS_TRANS_RELOG here instead because I need to use that for random buffer relogging later in the series, so it accomplished both at least for the time being. For a non-RFC series I could look into moving that flag into the reservation, relegating TRANS_RELOG to debug mode and letting the test code use it from there. > Reviewed-by: Allison Collins > Thanks! Brian > > { > > struct xlog_ticket *tic; > > @@ -3431,6 +3434,9 @@ xlog_ticket_alloc( > > return NULL; > > unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes); > > + /* double the overhead for the relog transaction */ > > + if (relog) > > + unit_res += (unit_res - unit_bytes); > > atomic_set(&tic->t_ref, 1); > > tic->t_task = current; > > diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h > > index 6d2f30f42245..f1089a4b299c 100644 > > --- a/fs/xfs/xfs_log.h > > +++ b/fs/xfs/xfs_log.h > > @@ -123,7 +123,8 @@ int xfs_log_reserve(struct xfs_mount *mp, > > int count, > > struct xlog_ticket **ticket, > > uint8_t clientid, > > - bool permanent); > > + bool permanent, > > + bool relog); > > int xfs_log_regrant(struct xfs_mount *mp, struct xlog_ticket *tic); > > void xfs_log_ungrant_bytes(struct xfs_mount *mp, int bytes); > > void xfs_log_unmount(struct xfs_mount *mp); > > diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c > > index b43f0e8f43f2..1c48e95402aa 100644 > > --- a/fs/xfs/xfs_log_cil.c > > +++ b/fs/xfs/xfs_log_cil.c > > @@ -37,7 +37,7 @@ xlog_cil_ticket_alloc( > > { > > struct xlog_ticket *tic; > > - tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, > > + tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, false, false, > > KM_NOFS); > > /* > > diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h > > index ec22c7a3867f..08d8ff9bce1a 100644 > > --- a/fs/xfs/xfs_log_priv.h > > +++ b/fs/xfs/xfs_log_priv.h > > @@ -465,6 +465,7 @@ xlog_ticket_alloc( > > int count, > > char client, > > bool permanent, > > + bool relog, > > xfs_km_flags_t alloc_flags); > > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > > index 4fbe11485bbb..1b25980315bd 100644 > > --- a/fs/xfs/xfs_trans.c > > +++ b/fs/xfs/xfs_trans.c > > @@ -177,6 +177,7 @@ xfs_trans_reserve( > > */ > > if (resp->tr_logres > 0) { > > bool permanent = false; > > + bool relog = (tp->t_flags & XFS_TRANS_RELOG); > > ASSERT(tp->t_log_res == 0 || > > tp->t_log_res == resp->tr_logres); > > @@ -199,7 +200,7 @@ xfs_trans_reserve( > > resp->tr_logres, > > resp->tr_logcount, > > &tp->t_ticket, XFS_TRANSACTION, > > - permanent); > > + permanent, relog); > > } > > if (error) > > >