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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 5E9B8C2D0A3 for ; Thu, 29 Oct 2020 14:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB1F62087D for ; Thu, 29 Oct 2020 14:57:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bTYuNixG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727708AbgJ2O5r (ORCPT ); Thu, 29 Oct 2020 10:57:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725782AbgJ2O5r (ORCPT ); Thu, 29 Oct 2020 10:57:47 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 565CAC0613CF; Thu, 29 Oct 2020 07:57:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=gaixN9Bvdo5h62VzxGq1fbBr5CvrRZrgy2xdLXcGzLE=; b=bTYuNixGSW2EZao7BIhpVMoBkg Fnfsb0miEeUi3RCG985nAhHBTRXcZ5zUyXS69dio+GuELyGkENctUrl4Si3aPWCXxI9R681ZfZjUb FfnzHqlfL6psaiXl1i+23BNkSEYxmg9iFWriVvp4QfG3iorYGmwxddxjuoFqNQg8LkBZ20KWgGzCR 3VPByv+8ikppMJVye3Zvksowg+Q87VfPAephQ4TPxKsSRUGsqEvKk1gLB+rt2laTKdVPwKewgXJQQ YCe4CkT2Bs/wAVsrqwBh/Cz6SUFnogZTvBB+LW6NHCdfQhfTtoDN4CdsdkGj82up76AVXl5Jlzpld rE/iUJJg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kY9N2-00056S-3U; Thu, 29 Oct 2020 14:57:44 +0000 Date: Thu, 29 Oct 2020 14:57:43 +0000 From: Christoph Hellwig To: Sebastian Andrzej Siewior Cc: Christoph Hellwig , linux-block@vger.kernel.org, Thomas Gleixner , David Runge , linux-rt-users@vger.kernel.org, Jens Axboe , linux-kernel@vger.kernel.org, Peter Zijlstra , Daniel Wagner , Mike Galbraith , Sagi Grimberg Subject: Re: [PATCH 3/3] blk-mq: Use llist_head for blk_cpu_done Message-ID: <20201029145743.GA19379@infradead.org> References: <20201028065616.GA24449@infradead.org> <20201028141251.3608598-1-bigeasy@linutronix.de> <20201028141251.3608598-3-bigeasy@linutronix.de> <20201029131212.dsulzvsb6pahahbs@linutronix.de> <20201029140536.GA6376@infradead.org> <20201029145623.3zry7o6nh6ks5tjj@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201029145623.3zry7o6nh6ks5tjj@linutronix.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Thu, Oct 29, 2020 at 03:56:23PM +0100, Sebastian Andrzej Siewior wrote: > On 2020-10-29 14:05:36 [+0000], Christoph Hellwig wrote: > > Well, usb-storage obviously seems to do it, and the block layer > > does not prohibit it. > > Also loop, nvme-tcp and then I stopped looking. > Any objections about adding local_bh_disable() around it? To me it seems like the whole IPI plus potentially softirq dance is a little pointless when completing from process context. Sagi, any opinion on that from the nvme-tcp POV?