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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2D58C4332F for ; Wed, 16 Nov 2022 11:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239053AbiKPLJE (ORCPT ); Wed, 16 Nov 2022 06:09:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238970AbiKPLIk (ORCPT ); Wed, 16 Nov 2022 06:08:40 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 155305289C for ; Wed, 16 Nov 2022 02:54:38 -0800 (PST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1668596076; 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=RwogQg4RY0UhxtFrKFf6UzwXviWVQCEE9KejmIIuHqE=; b=CBYdkqt/4TiJz6Kdgc75MiIA8BbtfFAnCdylA2ASfJnM5tC0dovDGOFmlCFY/r/laPuYij 2KkSOonnzeI2HOIwwWrkUN8SkJQIFZC/fPr6NC5O6gSpRgRbzgJpzaQ9uCx8LygaWQi2F5 QdZGTazusNzho4jKELHvuDNm02O9UQ9DzVjIfIR/tFQ3yVlvnhN9ulaC7Q4rQweS/6ANS3 lNjfg7Ay8vh26+qwZxTpZKjNuuqIoBpc8bnqF+8K4h0odK8iXRnet2VG9oCHp4UAe9j5sU /Gjdug9ZZvR7mfw3MAk372UThDxVSOImg/jclZL7Y65nAq0h7zQTOvaF8savCA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1668596076; 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=RwogQg4RY0UhxtFrKFf6UzwXviWVQCEE9KejmIIuHqE=; b=RfG0xiamJWgNPnV1LgDAj927Kq+9jSbJgYO/V9fyJHT7PmNHi1fgY2RCLSTWoQWKUo3JBt 7K7pvFFlwb/jAiBQ== To: Angus Chen , "Michael S. Tsirkin" Cc: "linux-kernel@vger.kernel.org" , Ming Lei , Jason Wang Subject: RE: IRQ affinity problem from virtio_blk In-Reply-To: References: <87v8nfrhbw.ffs@tglx> <20221115174152-mutt-send-email-mst@kernel.org> <87sfijrf9o.ffs@tglx> <87o7t7rec7.ffs@tglx> Date: Wed, 16 Nov 2022 11:54:35 +0100 Message-ID: <87iljfqidw.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 16 2022 at 00:46, Angus Chen wrote: >> On Wed, Nov 16 2022 at 00:04, Thomas Gleixner wrote: >> >>> But then it also has another 79 vectors put aside for the other queues, > en,it not the truth,in fact ,I just has one queue for one virtio_blk. Which does not matter. See my reply to Michael. It's ONE vector per CPU and block device. > Nov 14 11:48:45 localhost kernel: virtio_blk virtio181: 1/0/0 default/read/poll queues > Nov 14 11:48:45 localhost kernel: virtio_blk virtio181: [vdpr] 20480 512-byte logical blocks (10.5 MB/10.0 MiB) > Nov 14 11:48:46 localhost kernel: virtio-pci 0000:37:16.4: enabling device (0000 -> 0002) > Nov 14 11:48:46 localhost kernel: virtio-pci 0000:37:16.4: virtio_pci: leaving for legacy driver > Nov 14 11:48:46 localhost kernel: virtio_blk virtio182: 1/0/0 default/read/poll queues---------the virtio182 means index 182. > Nov 14 11:48:46 localhost kernel: vp_find_vqs_msix return err=-28-----------------------------the first time we get 'no space' error from irq subsystem. That's close to 200 virtio devices and the vector space is exhausted. Works as expected. Interrupt vectors are a limited resource on x86 and not only on x86. Not any different from any other resource. Thanks, tglx