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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E07D4CA9EC7 for ; Thu, 31 Oct 2019 02:03:48 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AEB052080F for ; Thu, 31 Oct 2019 02:03:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sourceforge.net header.i=@sourceforge.net header.b="eswdIaDz"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sf.net header.i=@sf.net header.b="XYL8qy9g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AEB052080F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1iPzoQ-00014N-Ny; Thu, 31 Oct 2019 02:03:46 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1iPzoP-00014D-SZ for linux-f2fs-devel@lists.sourceforge.net; Thu, 31 Oct 2019 02:03:45 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:CC:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=0anzFgkj3RFTdaj4qaHbkTCuoUxzauKwFvbdiuz4ASo=; b=eswdIaDzIU6DYMEGntjmcxSIos VnzcsiBUMH4rPtUoT5ANh7Ii/AOV9wUDP5SYJBZUKhqMzc88/moWqWGRO0uQmqXyrkbefZOq6NljT W7Mj9XpICEPfVEKzezp/eQNFWvTD8IXFWNYwQaPsfFTMjoMu1vuN1C+DIAz0f/RaAjzo=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=0anzFgkj3RFTdaj4qaHbkTCuoUxzauKwFvbdiuz4ASo=; b=XYL8qy9gK2b5x5upEisqMrxogR Vcq+TNZQXfOzO7zraVeR90nVMOCjeovG71b5xPFJD70dsK8o1k//SEhtiNLT3AfWupiGhJxirrGwi ldIEU01dhpTIWRO4GeqjofDjQyLqV9qog0X8dSKVnmqiVS4ie2bdejW6FyqUMnfn8ukU=; Received: from szxga07-in.huawei.com ([45.249.212.35] helo=huawei.com) by sfi-mx-3.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1iPzoN-00BiuQ-Te for linux-f2fs-devel@lists.sourceforge.net; Thu, 31 Oct 2019 02:03:45 +0000 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 63DA9B70C12BC89C0E01; Thu, 31 Oct 2019 10:03:32 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.204) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 31 Oct 2019 10:03:22 +0800 To: "Theodore Y. Ts'o" , Gao Xiang References: <20191030035518.65477-1-gaoxiang25@huawei.com> <20aa40bd-280d-d223-9f73-d9ed7dbe4f29@huawei.com> <20191030091542.GA24976@architecture4> <19a417e6-8f0e-564e-bc36-59bfc883ec16@huawei.com> <20191030104345.GB170703@architecture4> <20191030151444.GC16197@mit.edu> From: Chao Yu Message-ID: <61fc6d47-1cb3-4646-d155-444cff0b5b3e@huawei.com> Date: Thu, 31 Oct 2019 10:03:21 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20191030151444.GC16197@mit.edu> Content-Language: en-US X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected X-Headers-End: 1iPzoN-00BiuQ-Te Subject: Re: [f2fs-dev] [PATCH] f2fs: bio_alloc should never fail X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 2019/10/30 23:14, Theodore Y. Ts'o wrote: > On Wed, Oct 30, 2019 at 06:43:45PM +0800, Gao Xiang wrote: >>> You're right, in low memory scenario, allocation with bioset will be faster, as >>> you mentioned offline, maybe we can add/use a priviate bioset like btrfs did >>> rather than using global one, however, we'd better check how deadlock happen >>> with a bioset mempool first ... >> >> Okay, hope to get hints from Jaegeuk and redo this patch then... > > It's not at all clear to me that using a private bioset is a good idea > for f2fs. That just means you're allocating a separate chunk of > memory just for f2fs, as opposed to using the global pool. That's an > additional chunk of non-swapable kernel memory that's not going to be > available, in *addition* to the global mempool. > > Also, who else would you be contending for space with the global > mempool? It's not like an mobile handset is going to have other users > of the global bio mempool. > > On a low-end mobile handset, memory is at a premium, so wasting memory > to no good effect isn't going to be a great idea. You're right, it looks that the purpose that btrfs added private bioset is to avoid abusing bio internal fields (via commit 9be3395bcd4a), f2fs has no such reason to do that now. Thanks, > > Regards, > > - Ted > . > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel