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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1D476C83F22 for ; Tue, 15 Jul 2025 19:39:47 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ublSS-0008Ay-D0; Tue, 15 Jul 2025 15:36:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubkxI-0004AI-KP for qemu-devel@nongnu.org; Tue, 15 Jul 2025 15:04:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubkxG-0001QK-Ni for qemu-devel@nongnu.org; Tue, 15 Jul 2025 15:04:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752606281; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jwt5Mohty/49Ops6zWjl3ddGYpwcfvV3jj65uyvQ3wQ=; b=c4j9g7z4ECbH41oKZpGVN15x6+gCSnQVlr4XSSeNmgILGvZZPfS9Ez4GGhlBi51WQOJmWD v5veAi+87N4XazSCaogpaD7QVEyqNGfF4ZiEeOCrudnre3gxqdrfhwyZkgMN5X9satyvUC ASaPRrySNnjOGI6IB8jkN8ZLLv7stSc= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-606-91uSZhf0N5-xU644URNtvQ-1; Tue, 15 Jul 2025 15:04:39 -0400 X-MC-Unique: 91uSZhf0N5-xU644URNtvQ-1 X-Mimecast-MFC-AGG-ID: 91uSZhf0N5-xU644URNtvQ_1752606279 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DB54D19560B2; Tue, 15 Jul 2025 19:04:38 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.44.34.84]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 35C7C197702B; Tue, 15 Jul 2025 19:04:36 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 29/57] file-posix: Fix aio=threads performance regression after enablign FUA Date: Tue, 15 Jul 2025 21:03:02 +0200 Message-ID: <20250715190330.378764-30-kwolf@redhat.com> In-Reply-To: <20250715190330.378764-1-kwolf@redhat.com> References: <20250715190330.378764-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org For aio=threads, we're currently not implementing REQ_FUA in any useful way, but just do a separate raw_co_flush_to_disk() call. This changes behaviour compared to the old state, which used bdrv_co_flush() with its optimisations. As a quick fix, call bdrv_co_flush() again like before. Eventually, we can use pwritev2() to make use of RWF_DSYNC if available, but we'll still have to keep this code path as a fallback, so this fix is required either way. While the fix itself is a one-liner, some new graph locking annotations are needed to convince TSA that the locking is correct. Cc: qemu-stable@nongnu.org Fixes: 984a32f17e8d ("file-posix: Support FUA writes") Buglink: https://issues.redhat.com/browse/RHEL-96854 Reported-by: Tingting Mao Signed-off-by: Kevin Wolf Message-ID: <20250625085019.27735-1-kwolf@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/file-posix.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 9b5f08ccb2..8c738674ce 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2564,9 +2564,9 @@ static inline bool raw_check_linux_aio(BDRVRawState *s) } #endif -static int coroutine_fn raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, - uint64_t bytes, QEMUIOVector *qiov, int type, - int flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, uint64_t bytes, + QEMUIOVector *qiov, int type, int flags) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; @@ -2625,7 +2625,7 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, ret = raw_thread_pool_submit(handle_aiocb_rw, &acb); if (ret == 0 && (flags & BDRV_REQ_FUA)) { /* TODO Use pwritev2() instead if it's available */ - ret = raw_co_flush_to_disk(bs); + ret = bdrv_co_flush(bs); } goto out; /* Avoid the compiler err of unused label */ @@ -2660,16 +2660,16 @@ out: return ret; } -static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset, - int64_t bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, + QEMUIOVector *qiov, BdrvRequestFlags flags) { return raw_co_prw(bs, &offset, bytes, qiov, QEMU_AIO_READ, flags); } -static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, int64_t offset, - int64_t bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, + QEMUIOVector *qiov, BdrvRequestFlags flags) { return raw_co_prw(bs, &offset, bytes, qiov, QEMU_AIO_WRITE, flags); } @@ -3606,10 +3606,11 @@ static int coroutine_fn raw_co_zone_mgmt(BlockDriverState *bs, BlockZoneOp op, #endif #if defined(CONFIG_BLKZONED) -static int coroutine_fn raw_co_zone_append(BlockDriverState *bs, - int64_t *offset, - QEMUIOVector *qiov, - BdrvRequestFlags flags) { +static int coroutine_fn GRAPH_RDLOCK +raw_co_zone_append(BlockDriverState *bs, + int64_t *offset, + QEMUIOVector *qiov, + BdrvRequestFlags flags) { assert(flags == 0); int64_t zone_size_mask = bs->bl.zone_size - 1; int64_t iov_len = 0; -- 2.50.1