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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 CCAE1C33CB7 for ; Tue, 28 Jan 2020 00:17:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8D4EC24656 for ; Tue, 28 Jan 2020 00:17:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ocy2wX7g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D4EC24656 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BD0A56B0008; Mon, 27 Jan 2020 19:17:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B31966B000A; Mon, 27 Jan 2020 19:17:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FBFA6B000C; Mon, 27 Jan 2020 19:17:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0250.hostedemail.com [216.40.44.250]) by kanga.kvack.org (Postfix) with ESMTP id 8ACC16B0008 for ; Mon, 27 Jan 2020 19:17:03 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 4BC4A181AEF09 for ; Tue, 28 Jan 2020 00:17:03 +0000 (UTC) X-FDA: 76425127926.04.wish44_5aa1458766159 X-HE-Tag: wish44_5aa1458766159 X-Filterd-Recvd-Size: 4584 Received: from mail-pf1-f196.google.com (mail-pf1-f196.google.com [209.85.210.196]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Jan 2020 00:17:02 +0000 (UTC) Received: by mail-pf1-f196.google.com with SMTP id q8so5701658pfh.7 for ; Mon, 27 Jan 2020 16:17:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=7ENo+LQFzsHhuty3BkKJoKSguVUYkFockJe29Qo4mpc=; b=ocy2wX7gUdRsBNsZtjkPnol+rZ0Sop0TW/0noNZIYQe9cywJ4kuUDLVz6W/4bZa1JN Vd69qPExlyDn3MiBXaWe+VvVgp0zy3YRP7D4FGETClcNbSREVFMPWOSZs2h63TUPp5Y1 THEdG1kMsLAA4yju/MOS+H8eEnnler7ddnjDtHvOThEauG1iq44o6jm8hfoy5ws158K2 f+vxjtb++SGSDHg7XWuch2FiOImDaMMebd1nTD3TsZk96lu3uR5RXVhKyYqDrIcUsrbu uC3by1mmMITnfCvhWH8dP5yUC1YVRtCfFW9PxEPO2OVCnqIeuPlrVsE5w8dWcJAP9MQu mGjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=7ENo+LQFzsHhuty3BkKJoKSguVUYkFockJe29Qo4mpc=; b=rv7KaDWS3pUFuOyvVSGBtT9nqJHwEjPwSF7FBbfJKmVVHjW9OUoP21A9nZ2v3i1V2/ ZejggogYK+v4JYsxIJiUUyW+os+JFFKGgmRvimeb/hrOw+wBFsQHUQ80YIC+U77oBeAV 3JimuVVLb195wCUn4UsjDWd39uURlbNCf3YVZt9mbGZT12N1g+fZ/p5SFsETWRA6y0eX 5NdVpXDhhIrqxxJ7wpZpLJ+JVL2waPombIjFHOu64IEvMxf7jmwIQ710q8XmLwYJLJaL QtEmnTPIcVksJZE1I4Z+jyMo3seddti53vrmC53lugX//wVt3SPXxXJJtaleLIDDsaSa GJdA== X-Gm-Message-State: APjAAAW1F0HjUeQWs4RzZ20RGdWdK5/ZefbB8wDwzZLlBrlxD5ctC2m5 ZYmeteM1iUD4qw8ue7vz9ac= X-Google-Smtp-Source: APXvYqxvtzXGZuKMApqovR5A3qE1li5m7ePPP7dsGl0yzPx5L9d58S5ZdqIYJrNtvnpx/R9nRTBvHw== X-Received: by 2002:a63:2ad8:: with SMTP id q207mr22011778pgq.45.1580170621689; Mon, 27 Jan 2020 16:17:01 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id q28sm11301461pfl.153.2020.01.27.16.17.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jan 2020 16:17:00 -0800 (PST) From: Minchan Kim To: Andrew Morton Cc: LKML , linux-mm , linux-api@vger.kernel.org, oleksandr@redhat.com, Suren Baghdasaryan , Tim Murray , Daniel Colascione , Sandeep Patil , Sonny Rao , Brian Geffon , Michal Hocko , Johannes Weiner , Shakeel Butt , John Dias , Joel Fernandes , Minchan Kim Subject: [PATCH v3 3/5] mm/madvise: employ mmget_still_valid for write lock Date: Mon, 27 Jan 2020 16:16:39 -0800 Message-Id: <20200128001641.5086-4-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog In-Reply-To: <20200128001641.5086-1-minchan@kernel.org> References: <20200128001641.5086-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Oleksandr Natalenko Do the very same trick as we already do since 04f5866e41fb. KSM hints will require locking mmap_sem for write since they modify vm_flags, so for remote KSM hinting this additional check is needed. Signed-off-by: Oleksandr Natalenko Signed-off-by: Minchan Kim --- mm/madvise.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/madvise.c b/mm/madvise.c index 00ffa7e92f79..bc0a72dbf80e 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1061,6 +1061,8 @@ static int madvise_common(struct task_struct *task,= struct mm_struct *mm, if (write) { if (down_write_killable(&mm->mmap_sem)) return -EINTR; + if (current->mm !=3D mm && !mmget_still_valid(mm)) + goto skip_mm; } else { down_read(&mm->mmap_sem); } @@ -1111,6 +1113,7 @@ static int madvise_common(struct task_struct *task,= struct mm_struct *mm, } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else --=20 2.25.0.341.g760bfbb309-goog