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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28641C4332F for ; Fri, 21 Oct 2022 13:22:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=iFw/cDSlPBuBVXVGmaUBhsnxl5dRRkaxCHj+IqELRZc=; b=RksRmMmPAM4bnMOCttcQnrDeER TUmXNWFPTaUJ9bUgzja+a96abnEJAiSTLU6LJ5CojrNVAp68EWrEbVw5tGImVDYyh489G0JteF1n7 uKf7amBQuw2mPby79NP89xo4MP+7jIbPs11updQiNKynfRiUp0PK+WWh9ZmUQQ6JgR2GaSMVy7Jpx /IBecrCvQ4zUKyj0NE+pOyOrM/no+LNwi1eH109ibuuMZXAqBRG9236U6egoH1YN54sBgagt9Da4H fDA9MlNxSyBMz/R0wJzlp+YhiUhgEIAtosgxTrNsgh7dgULv0UDPSklQThMZGzpuYrPZdCj2i7c9Y TWSNtVBQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olryk-007u19-01; Fri, 21 Oct 2022 13:22:26 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1olryc-007twP-DN for linux-nvme@lists.infradead.org; Fri, 21 Oct 2022 13:22:23 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id E11CA68B05; Fri, 21 Oct 2022 15:22:14 +0200 (CEST) Date: Fri, 21 Oct 2022 15:22:14 +0200 From: Christoph Hellwig To: Chao Leng Cc: Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg , Ming Lei , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org Subject: Re: [PATCH 3/8] blk-mq: move the srcu_struct used for quiescing to the tagset Message-ID: <20221021132214.GC22327@lst.de> References: <20221020105608.1581940-1-hch@lst.de> <20221020105608.1581940-4-hch@lst.de> <46ce9b02-7474-22a7-f8c2-10f46e88853a@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46ce9b02-7474-22a7-f8c2-10f46e88853a@huawei.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221021_062218_644744_AA8750F4 X-CRM114-Status: GOOD ( 13.70 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, Oct 21, 2022 at 03:16:50PM +0800, Chao Leng wrote: >> struct list_head tag_list; >> + struct srcu_struct srcu; > srcu_struct size is more than 50+ KB, it is waste for the tagset which do not set > the BLK_MQ_F_BLOCKING, and most tagsets do not set the BLK_MQ_F_BLOCKING. > Maybe we can define "srcu" as a pointer, and allocate the memory in blk_mq_alloc_tag_set > just for tagset which set the BLK_MQ_F_BLOCKING. I guess we could do that. Still better than the variable sized struct. p.s. any chance you could properly trim your replies? I took me a while to find your comment in the sea of quotes.