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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01BE8C433F5 for ; Tue, 15 Mar 2022 22:20:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4A4CE6B0071; Tue, 15 Mar 2022 18:20:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 454786B0072; Tue, 15 Mar 2022 18:20:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31C5B8D0001; Tue, 15 Mar 2022 18:20:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 24A446B0071 for ; Tue, 15 Mar 2022 18:20:57 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id DFBB361724 for ; Tue, 15 Mar 2022 22:20:56 +0000 (UTC) X-FDA: 79248041712.12.C5E9219 Received: from mail-pf1-f176.google.com (mail-pf1-f176.google.com [209.85.210.176]) by imf29.hostedemail.com (Postfix) with ESMTP id 622D6120007 for ; Tue, 15 Mar 2022 22:20:56 +0000 (UTC) Received: by mail-pf1-f176.google.com with SMTP id a5so1200065pfv.2 for ; Tue, 15 Mar 2022 15:20:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=84kFTOf9/F1bpdxHLGKdmzF1pTCG4mq3396ASbcsPH0=; b=S6cKaJtz5ujUV0DCCwnZC3p3N4rVdwVp2PLbBPZAmCuTZTB0i6HNT8QMptZSHmuGkp lsv0iFjmSkdLqJcNKzqKUUDyvKpS9W34al05N1tqh39whL1PwZIZsOdUwqHJQKCJe8gn YlzqJQfNKUMiwF9PIELmslwzxkeICml7G7Epms9FgQC0Ap5rqviMF6GX3Xn4dtNx4px5 ZrQvK8E9518ngBf5PwMEGXnaOyWOz9kcHkL4lnPNZn+k3/MwY33VpSlnkLQoEeTDwIcu VMjI7mBxz28QWTqH64lJj2AZZWZIC2a28yJvuEMcq0ZQtQwN0Nmtuy9X9nBWm4H5PIJL JttQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=84kFTOf9/F1bpdxHLGKdmzF1pTCG4mq3396ASbcsPH0=; b=40+W9FIG0/fcKGuSK0LUaEnJXJADtFvbHPuy73Is3mRf5oQ4aJeylrQFPJ2Tdl84Jv vgJAAWrr9QgGkDO0911PyHcN9gLYjL8McZJYtsV1pqPb3/tmqEZHLUVjXB6MhDBT2OyW uG8oSNrw566IKzkQ7VKVulcGQNotNY29sNjgcwbjTCOGPEtKtf9ERANC3xQMMfkPwojf 8nPwlGcLYbzHYCa6VNxWUJvRTLVRfMI2XFt9V0vWT1mANmR0UaEFxd56TLEE1XKaYi2y ne2MQ/8NtUfLa86os9ut8Kgob8LgyLjASNxTRp97SAQzN8jO0NJ6SfW06+cBRAB3aU2Z OqxQ== X-Gm-Message-State: AOAM531e+M4yhmUIpJDfFcXlz9eOp7GvOSd592Hk5V2zbfzDIvZ+tv+w aLQ3oNHQBKD147+9macgZdY= X-Google-Smtp-Source: ABdhPJxPhbkHWHq5TAaAy1B2Kg+asrvXDmUsyIHvqWnKaqzN5CfQMU5J53F1xwWQl7jWU5H2aeS6jA== X-Received: by 2002:a65:424a:0:b0:375:6d8b:8d44 with SMTP id d10-20020a65424a000000b003756d8b8d44mr26272327pgq.170.1647382855304; Tue, 15 Mar 2022 15:20:55 -0700 (PDT) Received: from google.com ([2620:15c:211:201:7484:dc22:fe49:91cb]) by smtp.gmail.com with ESMTPSA id y32-20020a056a001ca000b004fa201a613fsm85131pfw.196.2022.03.15.15.20.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Mar 2022 15:20:54 -0700 (PDT) Date: Tue, 15 Mar 2022 15:20:52 -0700 From: Minchan Kim To: Charan Teja Kalla Cc: akpm@linux-foundation.org, surenb@google.com, vbabka@suse.cz, rientjes@google.com, sfr@canb.auug.org.au, edgararriaga@google.com, nadav.amit@gmail.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "# 5 . 10+" Subject: Re: [PATCH V2,1/2] mm: madvise: return correct bytes advised with process_madvise Message-ID: References: <125b61a0edcee5c2db8658aed9d06a43a19ccafc.1647008754.git.quic_charante@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <125b61a0edcee5c2db8658aed9d06a43a19ccafc.1647008754.git.quic_charante@quicinc.com> X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=S6cKaJtz; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none); spf=pass (imf29.hostedemail.com: domain of minchan.kim@gmail.com designates 209.85.210.176 as permitted sender) smtp.mailfrom=minchan.kim@gmail.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 622D6120007 X-Stat-Signature: 8q4zw7nwh9j6ik7jdccj5qxg5fyofybc X-HE-Tag: 1647382856-549413 X-Bogosity: Ham, tests=bogofilter, spamicity=0.034798, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Mar 11, 2022 at 08:59:05PM +0530, Charan Teja Kalla wrote: > The process_madvise() system call returns error even after processing > some VMA's passed in the 'struct iovec' vector list which leaves the > user confused to know where to restart the advise next. It is also > against this syscall man page[1] documentation where it mentions that > "return value may be less than the total number of requested bytes, if > an error occurred after some iovec elements were already processed.". > > Consider a user passed 10 VMA's in the 'struct iovec' vector list of > which 9 are processed but one. Then it just returns the error caused on > that failed VMA despite the first 9 VMA's processed, leaving the user > confused about on which VMA it is failed. Returning the number of bytes > processed here can help the user to know which VMA it is failed on and > thus can retry/skip the advise on that VMA. > > [1]https://man7.org/linux/man-pages/man2/process_madvise.2.html. > > Fixes: ecb8ac8b1f14("mm/madvise: introduce process_madvise() syscall: an external memory hinting API") > Cc: # 5.10+ > Signed-off-by: Charan Teja Kalla Acked-by: Minchan Kim