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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5795C433EF for ; Thu, 14 Oct 2021 01:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4A0561056 for ; Thu, 14 Oct 2021 01:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229837AbhJNBpU (ORCPT ); Wed, 13 Oct 2021 21:45:20 -0400 Received: from m12-11.163.com ([220.181.12.11]:46890 "EHLO m12-11.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbhJNBpT (ORCPT ); Wed, 13 Oct 2021 21:45:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Date:From:Subject:Message-ID:MIME-Version; bh=XKVvQ n2X6uzeWYHLBs62kSCazfOZ5OQzKPuckB59ymw=; b=RONdr3F/hZ+unWXyMyhBa n1t6oR7+Xpv+1jrQbTlZMDW44XTUz2rqFbpTBVEwLE+GCb/ZU2Jzi/zKVBQAGUOC lkeJZxzDH57xxf3YiKmpFxe0kX+RN2GRKPJXjd7YzSXIAA2DBiSf37AV8Hlyjo7e FWa3dncjxqeQ3zDP3DhZ0Q= Received: from localhost (unknown [218.94.48.178]) by smtp7 (Coremail) with SMTP id C8CowACHfY0ki2dhl9gG1w--.29353S2; Thu, 14 Oct 2021 09:43:01 +0800 (CST) Date: Thu, 14 Oct 2021 09:42:59 +0800 From: Yue Hu To: Gao Xiang Cc: Yue Hu , xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org, huyue2@yulong.com, zhangwen@yulong.com Subject: Re: [PATCH] erofs: fix the per-CPU buffer decompression for small output size Message-ID: <20211014094259.00004ac5.zbestahu@163.com> In-Reply-To: References: <20211013092906.1434-1-zbestahu@gmail.com> <20211013211005.7bd9fc08.zbestahu@163.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CM-TRANSID: C8CowACHfY0ki2dhl9gG1w--.29353S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7AF1xCrWrJFWrXr48Gw45Wrg_yoW8XFW3pr WSkFy0ka4FqryUAr4Utr18ZFW3t3yxKr40q39YqFyrXF9Igrs3Gryktr48Wrs7X3Wru3Za yw4jganIv3y5CFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j0oGQUUUUU= X-Originating-IP: [218.94.48.178] X-CM-SenderInfo: p2eh23xdkxqiywtou0bp/xtbBLwQsEVUMOfTVtQABsj Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 Oct 2021 00:03:02 +0800 Gao Xiang wrote: > On Wed, Oct 13, 2021 at 09:10:05PM +0800, Yue Hu wrote: > > Hi Xiang, > > > > On Wed, 13 Oct 2021 19:51:55 +0800 > > Gao Xiang wrote: > > > > > Hi Yue, > > > > > > On Wed, Oct 13, 2021 at 05:29:05PM +0800, Yue Hu wrote: > > > > From: Yue Hu > > > > > > > > Note that z_erofs_lz4_decompress() will return a positive value if > > > > decompression succeeds. However, we do not copy_from_pcpubuf() due > > > > to !ret. Let's fix it. > > > > > > > > Signed-off-by: Yue Hu > > > > > > Thanks for catching this. This is a valid issue, but it has no real > > > impact to the current kernels since such pcluster in practice will be > > > !inplace_io and trigger "if (nrpages_out == 1 && !rq->inplace_io) {" > > > above for upstream strategies. > > > > > > Our customized lz4 implementation will return 0 if success instead, so > > > it has no issue to our previous products as well. > > > > Yes, i just find the issue when i try to implement a new feature of > > tail-packing inline compressed data. No problem in my current version. > > Yeah, please help update the return value of z_erofs_lz4_decompress() > and get rid of such unneeded fast path. OK, will update in next version. Thanks. > > Thanks, > Gao Xiang > > > > > Thanks. > > > > > > > > For such cases, how about updating z_erofs_lz4_decompress() to return > > > 0 if success instead rather than outputsize. Since I'll return 0 if > > > success for LZMA as well. > > > > > > Thanks, > > > Gao Xiang > >