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 0C6CFCCD1BE for ; Thu, 23 Oct 2025 11:52:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vBtnO-0007h2-BR; Thu, 23 Oct 2025 07:47:54 -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 1vBtn9-0006pC-46 for qemu-devel@nongnu.org; Thu, 23 Oct 2025 07:47:41 -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 1vBtn4-00024L-Gj for qemu-devel@nongnu.org; Thu, 23 Oct 2025 07:47:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1761220051; 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=UNE0pIwf7h3rmebQSyZfc4u59qBmEQ1w/M5TsGcOgUM=; b=DKLKE6R7pPOc6zt/foZ/O/HtG6OgORzJmQvthsP6xNzi98FFHMFGJ33pbFP5YFRHqmxWJy 8iOKAjT3V2kALj2ZwHTVCsKXRMV6fMApY+ZRaVTRV7o/Y6D51epMkNTI84NJqpQPmaV+rA 4ukuL3wg9cndncMmWNTHIOBXYzWdtqs= Received: from mx-prod-mc-03.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-296-lN_5q1_uPNGhVgSyTzERbw-1; Thu, 23 Oct 2025 07:47:27 -0400 X-MC-Unique: lN_5q1_uPNGhVgSyTzERbw-1 X-Mimecast-MFC-AGG-ID: lN_5q1_uPNGhVgSyTzERbw_1761220047 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B7B761956052; Thu, 23 Oct 2025 11:47:26 +0000 (UTC) Received: from redhat.com (unknown [10.45.225.90]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3E6851800452; Thu, 23 Oct 2025 11:47:24 +0000 (UTC) Date: Thu, 23 Oct 2025 13:47:21 +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 18/21] fuse: Implement multi-threading Message-ID: References: <20250701114437.207419-1-hreitz@redhat.com> <20250701114437.207419-19-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250701114437.207419-19-hreitz@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 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=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 Am 01.07.2025 um 13:44 hat Hanna Czenczek geschrieben: > FUSE allows creating multiple request queues by "cloning" /dev/fuse FDs > (via open("/dev/fuse") + ioctl(FUSE_DEV_IOC_CLONE)). > > We can use this to implement multi-threading. > > For configuration, we don't need any more information beyond the simple > array provided by the core block export interface: The FUSE kernel > driver feeds these FDs in a round-robin fashion, so all of them are > equivalent and we want to have exactly one per thread. > [...] > @@ -451,6 +553,16 @@ static void fuse_export_delete(BlockExport *blk_exp) > { > FuseExport *exp = container_of(blk_exp, FuseExport, common); > > + for (int i = 0; i < exp->num_queues; i++) { > + FuseQueue *q = &exp->queues[i]; > + > + /* Queue 0's FD belongs to the FUSE session */ > + if (i > 0 && q->fuse_fd >= 0) { Why not start the loop with i = 1 instead of starting at 0 and then not doing anything in the first iteration? (I love the >= 0, running FUSE over stdin must be fun. :-)) > + close(q->fuse_fd); > + } > + } > + g_free(exp->queues); > + > if (exp->fuse_session) { > if (exp->mounted) { > fuse_session_unmount(exp->fuse_session); Kevin