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a=rsa-sha256; c=relaxed/relaxed; d=stgolabs.net; s=dreamhost; t=1708457778; bh=hJt/IYVb0eRDuwpPuHvdH7KdNxea+aTwmt9C56h0Cws=; h=Date:From:To:Cc:Subject:Content-Type; b=bCLKgtoFrIDxE9TulzKX03YtzRwqsgpaiO1i9BXGIp+M/aijYBAeHDzbbNlnPTFyc ejaeFhjJd/gZ7Cdex0mXbkKVupxsDRzUyRQfjUFr4a+TS9h85+ECcC0H8pO18k8uIO n70U1MC5zJ7leo2cLL5eCevDb2kcBF+KXkdk7N2r+uAyWDj4anHZheabv8ot3oWU2g 2skaS3Y9t+PA+jyqDxj9kc8s/6SB6r6MnCR8wcc9xqDEnQpZIshjC77ywO5yv0tG/A VBCyvesPDEDOfUr+GoumHVd47XY3MrRVlMCopA/GxdHrGfbBklxsCikci5TlS3T+P0 Q/tNRI2Y7uAJA== Date: Tue, 20 Feb 2024 11:36:14 -0800 From: Davidlohr Bueso To: Linus Torvalds Cc: Tejun Heo , mpatocka@redhat.com, linux-kernel@vger.kernel.org, dm-devel@lists.linux.dev, msnitzer@redhat.com, ignat@cloudflare.com, damien.lemoal@wdc.com, bob.liu@oracle.com, houtao1@huawei.com, peterz@infradead.org, mingo@kernel.org, netdev@vger.kernel.org, allen.lkml@gmail.com, kernel-team@meta.com, Greg Kroah-Hartman , Alan Stern , linux-usb@vger.kernel.org, mchehab@kernel.org Subject: Re: [PATCH 5/8] usb: core: hcd: Convert from tasklet to BH workqueue Message-ID: <20240220193614.b2rbzxmbobp3cbv2@offworld> Mail-Followup-To: Linus Torvalds , Tejun Heo , mpatocka@redhat.com, linux-kernel@vger.kernel.org, dm-devel@lists.linux.dev, msnitzer@redhat.com, ignat@cloudflare.com, damien.lemoal@wdc.com, bob.liu@oracle.com, houtao1@huawei.com, peterz@infradead.org, mingo@kernel.org, netdev@vger.kernel.org, allen.lkml@gmail.com, kernel-team@meta.com, Greg Kroah-Hartman , Alan Stern , linux-usb@vger.kernel.org, mchehab@kernel.org References: <20240130091300.2968534-1-tj@kernel.org> <20240130091300.2968534-6-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20220429 On Tue, 20 Feb 2024, Linus Torvalds wrote: >Mauro - the BH workqueue should provide the same kind of latency as >the tasklets, and it would be good to validate early that yes, this >workqueue conversion works well in practice. Since you have an actual >real-life test-case, could you give it a try? In general I think it's worth pointing out that future conversions should still aim for an equivalent in task context, and now with disable/enable_work a lot opens up for regular wq conversions. If users/maintainers shout about latency, then use BH wq. Thanks, Davidlohr