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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 82E7CC47423 for ; Fri, 2 Oct 2020 13:39:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 494FB206E3 for ; Fri, 2 Oct 2020 13:39:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="d+z/rtGh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726569AbgJBNjS (ORCPT ); Fri, 2 Oct 2020 09:39:18 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:44140 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBNjR (ORCPT ); Fri, 2 Oct 2020 09:39:17 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 092DdCbP002579; Fri, 2 Oct 2020 13:39:12 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : message-id : references : date : in-reply-to : mime-version : content-type; s=corp-2020-01-29; bh=IGKJaZlfnNTO7i1ACoOSSaJeeqkjoUmn20eh8oo34nQ=; b=d+z/rtGhWiCJ9nhO4QwFqUb3sjZyFyx1kAFuEdHbEn3LVKDOlWWesQxkcRiQgbvQ8dg0 n6f8YIvWI5xJXAiVIw0wDyWLRiYiI23BSothepklnQfKCMtlkbEtv3hgzDmaIBE64Gkt Nmvp/PmET8no1hGOFIqDoIfCBzuGpeGjXYNiAbu77gUMPX7SYcOLVmK8FtYVtQPCel0+ LJrMhTDFj6dREwR/jGULuV8d6ibNkiVpB7sUE/Ci8l+sRRwwbFolDby2DPIBSsZKZ19/ DQEvNF2OwNgsiTWtFV4VGaD1I/5oHhChKGXNyHuwk5wzYwlfvI85X4gJ37aAH6X0cfVY 2Q== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 33sx9njych-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 02 Oct 2020 13:39:12 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 092DZsoO062792; Fri, 2 Oct 2020 13:39:08 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 33tfk3hnnd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 02 Oct 2020 13:39:08 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 092Dd7Ij026447; Fri, 2 Oct 2020 13:39:07 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 02 Oct 2020 06:39:06 -0700 To: Naohiro Aota Cc: linux-btrfs@vger.kernel.org, dsterba@suse.com, hare@suse.com, linux-fsdevel@vger.kernel.org, Johannes Thumshirn Subject: Re: [PATCH v8 01/41] block: add bio_add_zone_append_page From: "Martin K. Petersen" Organization: Oracle Corporation Message-ID: References: Date: Fri, 02 Oct 2020 09:39:04 -0400 In-Reply-To: (Naohiro Aota's message of "Fri, 2 Oct 2020 03:36:08 +0900") MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9761 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 spamscore=0 mlxscore=0 phishscore=0 adultscore=0 bulkscore=0 mlxlogscore=999 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2010020106 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9761 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 suspectscore=1 phishscore=0 mlxscore=0 lowpriorityscore=0 adultscore=0 clxscore=1011 spamscore=0 impostorscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2010020107 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Naohiro/Johannes, > Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which > is intended to be used by file systems that directly add pages to a bio > instead of using bio_iov_iter_get_pages(). Why use the hardware limit? For filesystem I/O we generally use the queue soft limit to prevent I/Os getting too big which can lead to very unpredictable latency in mixed workloads. max_zone_append_sectors also appears to be gated exclusively by hardware constraints. Is there user-controllable limit in place for append operations? -- Martin K. Petersen Oracle Linux Engineering