From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F0F5F38F95B for ; Tue, 1 Sep 2026 21:12:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788297123; cv=none; b=Au8KfuukLAJZy5x0x7WoGwEnskGV/E/WtBpQpqGwOpN5fvZKT5baAC12r9CixEYSGo9+Bs/ZsX8smNlcK38HPy3W3ZoUWTKVi8HTqB2zYg1AtJnmnrvltYyUgTNtd7g3M1XgNnNwsFuMsGW4Ow7qHWwX/JqTg9B4/UPsh0D43gM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788297123; c=relaxed/simple; bh=LITuoE5iRciuw395Oet//i5jt2ETRlXOCw08gIVlDc4=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=tXCtDF6uWczEs7S8CqGknLdEEbAjF2UOkiNosfFJcgrOUpAKQ2qjSmHsdklBptf9xYj+1BFtLhUJZjR+vzYn0MaqXVjFQibft9bONjPTS/zH0mi77QvxBu6NVIVnL5xp/EgBvJ/RyRNvY6ay5w4nOWqL5wTCzMrvck2T4X9jR9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=geJuFKbG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="geJuFKbG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D92871F00A3A; Tue, 1 Sep 2026 21:11:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788297119; bh=BfOoWegF+Sq6QHrTJQA+JbaGReMIOa+BkItA1J565/A=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=geJuFKbGg5n517DmFqdvVUKDwuE2i24h+IAgQbgufzi/fHbO6INK1DwVL4l6E5f5r aapkqhlNgmgQ0j9bzjAEh3hnm+MrEGIgRpy6dXUOiqC5koQ8rYP78PWteXqE1fOodf 9cEck7f5b9IzxRUyDlivjvx4+ABpZqkcAhr7xg+r55pujljWdvFWr0jhOIEPdYxIZa 1vv8LxXqUsA1LMi3mrqtvJe5hkALJan+2597bhBmqYrmMoDa1oHoyGCd47VmTIZ32X rhQfv8ccp5wvQRwlxcHIZ+Xh1hdTZrAHcCazO4GSJich+VUUVcM7lZyfn7QAgzJeWB dE4A1kyCUJG3A== Date: Tue, 01 Sep 2026 11:11:58 -1000 Message-ID: <92e520050991ea409925012255480655@kernel.org> From: Tejun Heo To: Yao Kai Cc: Lai Jiangshan , Breno Leitao , linux-kernel@vger.kernel.org, liuyongqiang Subject: Re: [QUESTION] workqueue: Reducing flush_workqueue() overhead for unbound workqueues In-Reply-To: <0a030145-c108-4365-ba2d-ac1973a1e352@huawei.com> References: <0a030145-c108-4365-ba2d-ac1973a1e352@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Hello, On Tue, Sep 01, 2026 at 04:46:06PM +0800, Yao Kai wrote: > Is there a recommended way to avoid this overhead for such case, > I would appreciate guidance on how this problem should be solved. Posted a patchset which makes flush_workqueue() visit only the pwqs which have been active since the last flush: https://lore.kernel.org/all/20260901210929.3092513-1-tj@kernel.org/ Can you please test whether it resolves the fsync latency issue you're seeing? Thanks. -- tejun