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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 A38F0C43331 for ; Thu, 2 Apr 2020 04:08:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 62750206E9 for ; Thu, 2 Apr 2020 04:08:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="YC0g/uHk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 62750206E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0BB6F8E0064; Thu, 2 Apr 2020 00:08:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 044EF8E000D; Thu, 2 Apr 2020 00:08:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E4F198E0064; Thu, 2 Apr 2020 00:08:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0109.hostedemail.com [216.40.44.109]) by kanga.kvack.org (Postfix) with ESMTP id C9F768E000D for ; Thu, 2 Apr 2020 00:08:58 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9072A482A for ; Thu, 2 Apr 2020 04:08:58 +0000 (UTC) X-FDA: 76661584356.09.legs16_4e54591b77217 X-HE-Tag: legs16_4e54591b77217 X-Filterd-Recvd-Size: 4991 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:08:58 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7EE6220B1F; Thu, 2 Apr 2020 04:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800537; bh=lmAm5QK2NT+s68OlObVTOjJScHCGfQBTrGTdok3TBg0=; h=Date:From:To:Subject:In-Reply-To:From; b=YC0g/uHk7Bm9/Wp+1SI0ceF+Uz9QtX6tEiRdOaRBq1eJKGgq+BbzvRXz4d0vY3rUa nVBvOnZInNCEcwano3jlNenIWBCZIaemH3frmJh3CgkWtfxiejnJtUiT9ZfFfkPv/I fWZ5ulNBEMKI+w6v8nTS9MqdDs7ZvJ8n42IPiD1A= Date: Wed, 01 Apr 2020 21:08:53 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, bgeffon@google.com, bobbypowers@gmail.com, cracauer@cons.org, david@redhat.com, dgilbert@redhat.com, dplotnikov@virtuozzo.com, gokhale2@llnl.gov, hannes@cmpxchg.org, hughd@google.com, jglisse@redhat.com, kirill@shutemov.name, linux-mm@kvack.org, mcfadden8@llnl.gov, mgorman@suse.de, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, rppt@linux.vnet.ibm.com, torvalds@linux-foundation.org, willy@infradead.org, xemul@openvz.org Subject: [patch 100/155] mm/gup: allow to react to fatal signals Message-ID: <20200402040853.kV3BL4oyi%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 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: Peter Xu Subject: mm/gup: allow to react to fatal signals The existing gup code does not react to the fatal signals in many code paths. For example, in one retry path of gup we're still using down_read() rather than down_read_killable(). Also, when doing page faults we don't pass in FAULT_FLAG_KILLABLE as well, which means that within the faulting process we'll wait in non-killable way as well. These were spotted by Linus during the code review of some other patches. Let's allow the gup code to react to fatal signals to improve the responsiveness of threads when during gup and being killed. Link: http://lkml.kernel.org/r/20200220160256.9887-1-peterx@redhat.com Signed-off-by: Peter Xu Tested-by: Brian Geffon Cc: Andrea Arcangeli Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Linus Torvalds Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Signed-off-by: Andrew Morton --- mm/gup.c | 12 +++++++++--- mm/hugetlb.c | 3 ++- 2 files changed, 11 insertions(+), 4 deletions(-) --- a/mm/gup.c~mm-gup-allow-to-react-to-fatal-signals +++ a/mm/gup.c @@ -864,7 +864,7 @@ static int faultin_page(struct task_stru if (*flags & FOLL_REMOTE) fault_flags |= FAULT_FLAG_REMOTE; if (locked) - fault_flags |= FAULT_FLAG_ALLOW_RETRY; + fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (*flags & FOLL_NOWAIT) fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; if (*flags & FOLL_TRIED) { @@ -1207,7 +1207,7 @@ int fixup_user_fault(struct task_struct address = untagged_addr(address); if (unlocked) - fault_flags |= FAULT_FLAG_ALLOW_RETRY; + fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; retry: vma = find_extend_vma(mm, address); @@ -1329,7 +1329,13 @@ retry: break; *locked = 1; - down_read(&mm->mmap_sem); + ret = down_read_killable(&mm->mmap_sem); + if (ret) { + BUG_ON(ret > 0); + if (!pages_done) + pages_done = ret; + break; + } ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED, pages, NULL, locked); --- a/mm/hugetlb.c~mm-gup-allow-to-react-to-fatal-signals +++ a/mm/hugetlb.c @@ -4344,7 +4344,8 @@ long follow_hugetlb_page(struct mm_struc if (flags & FOLL_WRITE) fault_flags |= FAULT_FLAG_WRITE; if (locked) - fault_flags |= FAULT_FLAG_ALLOW_RETRY; + fault_flags |= FAULT_FLAG_ALLOW_RETRY | + FAULT_FLAG_KILLABLE; if (flags & FOLL_NOWAIT) fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; _