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 C8229CCD1AB for ; Wed, 22 Oct 2025 12:58:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vBYPc-0001tx-QO; Wed, 22 Oct 2025 08:57:56 -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 1vBYPU-0001tK-3L for qemu-devel@nongnu.org; Wed, 22 Oct 2025 08:57:48 -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 1vBYPS-0002sk-7z for qemu-devel@nongnu.org; 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Wed, 22 Oct 2025 12:57:40 +0000 (UTC) Received: from redhat.com (unknown [10.45.225.168]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9C31B19560A2; Wed, 22 Oct 2025 12:57:38 +0000 (UTC) Date: Wed, 22 Oct 2025 14:57:35 +0200 From: Kevin Wolf To: Hanna Czenczek Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi , Markus Armbruster , Brian Song Subject: Re: [PATCH v3 16/21] block/export: Add multi-threading interface Message-ID: References: <20250701114437.207419-1-hreitz@redhat.com> <20250701114437.207419-17-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250701114437.207419-17-hreitz@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 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_H3=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=unavailable 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 Am 01.07.2025 um 13:44 hat Hanna Czenczek geschrieben: > Make BlockExportType.iothread an alternate between a single-thread > variant 'str' and a multi-threading variant '[str]'. > > In contrast to the single-thread setting, the multi-threading setting > will not change the BDS's context (and so is incompatible with the > fixed-iothread setting), but instead just pass a list to the export > driver, with which it can do whatever it wants. > > Currently no export driver supports multi-threading, so they all return > an error when receiving such a list. > > Suggested-by: Kevin Wolf > Acked-by: Markus Armbruster > Reviewed-by: Stefan Hajnoczi > Signed-off-by: Hanna Czenczek > diff --git a/include/block/export.h b/include/block/export.h > index 4bd9531d4d..ca45da928c 100644 > --- a/include/block/export.h > +++ b/include/block/export.h > @@ -32,8 +32,16 @@ typedef struct BlockExportDriver { > /* True if the export type supports running on an inactive node */ > bool supports_inactive; > > - /* Creates and starts a new block export */ > - int (*create)(BlockExport *, BlockExportOptions *, Error **); > + /* > + * Creates and starts a new block export. > + * > + * If the user passed a set of I/O threads for multi-threading, @multithread > + * is a list of the @multithread_count corresponding contexts (freed by the > + * caller). Note that @exp->ctx has no relation to that list. Maybe worth stating that it's NULL in the single threaded case? > + */ > + int (*create)(BlockExport *exp, BlockExportOptions *opts, > + AioContext *const *multithread, size_t multithread_count, > + Error **errp); > > /* > * Frees a removed block export. This function is only called after all > diff --git a/block/export/export.c b/block/export/export.c > index f3bbf11070..b733f269f3 100644 > --- a/block/export/export.c > +++ b/block/export/export.c > @@ -76,16 +76,26 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) > { > bool fixed_iothread = export->has_fixed_iothread && export->fixed_iothread; > bool allow_inactive = export->has_allow_inactive && export->allow_inactive; > + bool multithread = export->iothread && > + export->iothread->type == QTYPE_QLIST; > const BlockExportDriver *drv; > BlockExport *exp = NULL; > BlockDriverState *bs; > BlockBackend *blk = NULL; > AioContext *ctx; > + AioContext **multithread_ctxs = NULL; g_autofree? Kevin