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[23.128.96.18]) by mx.google.com with ESMTP id e8si260735ejj.540.2021.01.26.19.27.01; Tue, 26 Jan 2021 19:27:26 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=DrPEmKrc; dkim=neutral (no key) header.i=@linutronix.de header.b=HuTQnFwN; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731496AbhAZFFo (ORCPT + 99 others); Tue, 26 Jan 2021 00:05:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726646AbhAYJbU (ORCPT ); Mon, 25 Jan 2021 04:31:20 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 381D2C06174A; Mon, 25 Jan 2021 01:29:10 -0800 (PST) Date: Mon, 25 Jan 2021 10:29:08 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1611566948; 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=jku6Tec7q+qisOnosheK7vPMPoB+SzWJoKjJCzgdLxg=; b=DrPEmKrc4+G8WhLciMvGkpFc4uAI2a8BdHh8QU8pB3a+unm7cxOiq1DEOPoc1GTsSfd/3C frMHNk7Sam/2rNyhTkDRsamHk48BJNeIpcIsDCIpzmiErE7SAZu8YvZYgoJ65G8vOIYRsh c3x7EnfPf/BKR6Gqp73SzHCPFrxAiadldUqwkiXVhv1tqXRkuZshREBt5Zy8KuyJ5ZC/j0 uYg8OKkIe5Ip2erc1HJI6nOAqHjzUKFH/7+a7/24759mfkugEaei10WDQMY9DWKAXK09HC fHX+5hVbz/N2T9h1KEXN5sNgFnPKGTI2DCUKnMDRgZI5rJgwZFdYGb2ojph5tg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1611566948; 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=jku6Tec7q+qisOnosheK7vPMPoB+SzWJoKjJCzgdLxg=; b=HuTQnFwN9rYs6voYZat4Kwko1csP9h7nuja7LDtXWfVh9hWfcWxzyjMah87AWxEuaniJUT mrnNdDj6m6cH1+BQ== From: Sebastian Andrzej Siewior To: Christoph Hellwig Cc: Hannes Reinecke , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Axboe , Thomas Gleixner , Peter Zijlstra , Ingo Molnar Subject: Re: [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq Message-ID: <20210125092908.ntugyvnbyigxpoyl@linutronix.de> References: <20210123201027.3262800-1-bigeasy@linutronix.de> <20210123201027.3262800-3-bigeasy@linutronix.de> <30ce5ce2-8b9a-8873-4b37-c8720300942b@suse.de> <20210125082542.GC942655@infradead.org> <20210125083029.utnjqs2s3diqb5vx@linutronix.de> <20210125083248.GA945284@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210125083248.GA945284@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-01-25 08:32:48 [+0000], Christoph Hellwig wrote: > Well, I put it in quotes because I'm not sure what the exact effect > is. But we do delay these completions to the softirq now instead of > hardirq context, which at least in theory increases latency. OTOH it > might even have positive effects on the rest of the system. The last part is/was my motivation ;) Sebastian