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=-13.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 4C67AC35646 for ; Fri, 21 Feb 2020 19:26:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F3535206E2 for ; Fri, 21 Feb 2020 19:26:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="icakTwtY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3535206E2 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A30CD6B0006; Fri, 21 Feb 2020 14:26:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9E01B6B0007; Fri, 21 Feb 2020 14:26:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8A9226B0008; Fri, 21 Feb 2020 14:26:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 729076B0006 for ; Fri, 21 Feb 2020 14:26:41 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 06B3A824805A for ; Fri, 21 Feb 2020 19:26:41 +0000 (UTC) X-FDA: 76515116202.25.toad21_1d2b932bd1227 X-HE-Tag: toad21_1d2b932bd1227 X-Filterd-Recvd-Size: 10268 Received: from mail-ed1-f67.google.com (mail-ed1-f67.google.com [209.85.208.67]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 21 Feb 2020 19:26:40 +0000 (UTC) Received: by mail-ed1-f67.google.com with SMTP id c26so3723948eds.8 for ; Fri, 21 Feb 2020 11:26:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xr60A1dzj1G3mLhY1jqSdwMVifVQF6aHlkkVpy0bbho=; b=icakTwtYl5pI7U6NFJp2r+HgbtShFbRiXPZBLmgMOx0GSuOC44mvFu8ThHgk9SSMUn 4r5hs3AmplvrrDiQDtcZ5xX/qpDgb3/w1hcjG0sz3pZTDdQdVJA+ZV7ikcpX1vXiSl+b mUwQM9V88QfLiiv6ZPLxIoc3GDflxNT+mLd/QuQCZ9guGmM1vhTnoJW0LCG2u0cBBQAX l3uskjE5qyzoRgB1igCARjVzD1XUc23M/6gnHHB8sia6F6UBeZZm2OefqBR4zXb8lwkj oMwJuXGIcazxggPh+edkpIC+1qqPBxqaTfncaQonKQrVAdUjJKxUZfSp1bf0z/71AEhY XUwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xr60A1dzj1G3mLhY1jqSdwMVifVQF6aHlkkVpy0bbho=; b=W46wfFG2pBT3MBY9xLHPZrM6Gv9bDxgI2oRfL36VVGiff8BddplyLElRlt8iUYRMfe YdvytKBg0PdN61xx3DopWTQNenaUZSjRh21orPbCXpxq5VymvEW1v+KMhk79zX8KII0A I+ktqhyhkMhWBiolVRjOQAUBNaHoV8+5I/mf1GDRDVvZgX5L/J5DGUDndInU7QvF96uP XtV698AL1E+sPz56yB62BeS+2pEJIFRlOnGxxUwKv0haQOusPgyDK5ZynOCk1BduU0GY Cf+kqZOpYbk9QkRjwJ5hk3enRoflIuVR++BS9ci+/vOaQFibvVEt8usa7Zr3Y/qbUfEY Z/dQ== X-Gm-Message-State: APjAAAUw1icdT5MTlUmQ7h27IRdx6C3Yam/D8TEMZUYCfC0hrS4Gy134 /LPdHO7IHcYlYeOjaFtsg4IiyAznSqmZvk8KOPlCbA== X-Google-Smtp-Source: APXvYqy8vEdFmgXmuuacz26gihQ4SanMmW0EWiVxOCriNW08x3bQoHTba7lbgrwfZrbUhbDKzHSlvT1ampqGnakzHus= X-Received: by 2002:a17:906:6888:: with SMTP id n8mr7946052ejr.171.1582313198670; Fri, 21 Feb 2020 11:26:38 -0800 (PST) MIME-Version: 1.0 References: <20200220155353.8676-1-peterx@redhat.com> In-Reply-To: <20200220155353.8676-1-peterx@redhat.com> From: Brian Geffon Date: Fri, 21 Feb 2020 11:26:12 -0800 Message-ID: Subject: Re: [PATCH RESEND v6 00/16] mm: Page fault enhancements To: Peter Xu Cc: linux-mm , LKML , Andrea Arcangeli , Martin Cracauer , Linus Torvalds , Mike Rapoport , "Kirill A . Shutemov" , Johannes Weiner , "Dr . David Alan Gilbert" , David Hildenbrand , Bobby Powers , Maya Gokhale , Jerome Glisse , Mike Kravetz , Matthew Wilcox , Marty McFadden , Mel Gorman , Hugh Dickins , Denis Plotnikov , Pavel Emelyanov Content-Type: text/plain; charset="UTF-8" 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: I tested the entire patchset because I'm very interested in fault retries with userfaultfd and the series has been stable and worked well on x86. Tested-by: Brian Geffon On Thu, Feb 20, 2020 at 7:54 AM Peter Xu wrote: > > [Resend v6] > > This is v6 of the series. It is majorly a rebase to 5.6-rc2, nothing > else to be expected (plus some tests after the rebase). Instead of > rewrite the cover letter I decided to use what we have for v5. > > Adding extra CCs for both Bobby Powers and > Brian Geffon . > > Online repo: https://github.com/xzpeter/linux/tree/mm-pf-signal-retry > > Any review comment is appreciated. Thanks, > > =============== v5 cover letter ================== > > This is v5 of the series. As Matthew suggested, I split the previous > patch "mm: Return faster for non-fatal signals in user mode faults" > into a few smaller ones: > > 1. One patch to introduce fatal_signal_pending(), and use it in > archs that can directly apply > > 2. A few more patches to let the rest archs to use the new helper. > With that we can have an unified entry for signal detection > > 3. One last patch to change fatal_signal_pending() to detect > userspace non-fatal signal > > Nothing should have changed in the rest patches. Because the fault > retry patches will depend on the previous ones, I decided to simply > repost all the patches. > > Here's the new patchset layout: > > Patch 1-2: cleanup, and potential bugfix of hugetlbfs on fault retry > > Patch 3-9: let page fault to respond to non-fatal signals faster > > Patch 10: remove the userfaultfd NOPAGE emulation > > Patch 11-14: allow page fault to retry more than once > > Patch 15-16: let gup code to use FAULT_FLAG_KILLABLE too > > I would really appreciate any review comments for the series, > especially for the first two patches which IMHO are even not related > to this patchset and they should either cleanup or fix things. > > Smoke tested on x86 only. > > Thanks, > > v5: > - split "mm: Return faster for non-fatal signals in user mode faults" > into a few more patches, let all archs to use an unified entry for > fast signal handling (fatal_signal_pending) > > v4: > - use lore.kernel.org for all the links in commit messages [Kirill] > - one more patch ("mm/gup: Fix __get_user_pages() on fault retry of > hugetlb") to fix hugetlb path on fault retry > - one more patch ("mm/gup: Allow to react to fatal signals") to: > - use down_read_killable() properly [Linus] > - pass in FAULT_FLAG_KILLABLE for all GUP [Linus] > - one more patch ("mm/userfaultfd: Honor FAULT_FLAG_KILLABLE in fault > path") to let handle_userfaultfd() respect FAULT_FLAG_KILLABLE. > Should have no functional change after previous two new patches. > > v3: > - check fatal signals in __get_user_page_locked() [Linus] > - add r-bs > > v2: > - resent previous version, rebase only > > =============== v1 cover letter ================== > > This series is split out of userfaultfd-wp series to only cover the > general page fault changes, since it seems to make sense itself. > > Basically it does two things: > > (a) Allows the page fault handlers to be more interactive on not > only SIGKILL, but also the rest of userspace signals (especially > for user-mode faults), and, > > (b) Allows the page fault retry (VM_FAULT_RETRY) to happen for more > than once. > > I'm keeping the CC list as in uffd-wp v5, hopefully I'm not sending > too much spams... > > And, instead of writting again the cover letter, I'm just copy-pasting > my previous link here which has more details on why we do this: > > https://patchwork.kernel.org/cover/10691991/ > > The major change from that latest version should be that we introduced > a new page fault flag FAULT_FLAG_INTERRUPTIBLE as suggested by Linus > [1] to represents that we would like the fault handler to respond to > non-fatal signals. Also, we're more careful now on when to do the > immediate return of the page fault for such signals. For example, now > we'll only check against signal_pending() for user-mode page faults > and we keep the kernel-mode page fault patch untouched for it. More > information can be found in separate patches. > > The patchset is only lightly tested on x86. > > All comments are greatly welcomed. Thanks, > > [1] https://lkml.org/lkml/2019/6/25/1382 > > Peter Xu (16): > mm/gup: Rename "nonblocking" to "locked" where proper > mm/gup: Fix __get_user_pages() on fault retry of hugetlb > mm: Introduce fault_signal_pending() > x86/mm: Use helper fault_signal_pending() > arc/mm: Use helper fault_signal_pending() > arm64/mm: Use helper fault_signal_pending() > powerpc/mm: Use helper fault_signal_pending() > sh/mm: Use helper fault_signal_pending() > mm: Return faster for non-fatal signals in user mode faults > userfaultfd: Don't retake mmap_sem to emulate NOPAGE > mm: Introduce FAULT_FLAG_DEFAULT > mm: Introduce FAULT_FLAG_INTERRUPTIBLE > mm: Allow VM_FAULT_RETRY for multiple times > mm/gup: Allow VM_FAULT_RETRY for multiple times > mm/gup: Allow to react to fatal signals > mm/userfaultfd: Honor FAULT_FLAG_KILLABLE in fault path > > arch/alpha/mm/fault.c | 6 +-- > arch/arc/mm/fault.c | 35 +++++-------- > arch/arm/mm/fault.c | 7 +-- > arch/arm64/mm/fault.c | 26 +++------ > arch/hexagon/mm/vm_fault.c | 5 +- > arch/ia64/mm/fault.c | 5 +- > arch/m68k/mm/fault.c | 7 +-- > arch/microblaze/mm/fault.c | 5 +- > arch/mips/mm/fault.c | 5 +- > arch/nds32/mm/fault.c | 5 +- > arch/nios2/mm/fault.c | 7 +-- > arch/openrisc/mm/fault.c | 5 +- > arch/parisc/mm/fault.c | 8 ++- > arch/powerpc/mm/fault.c | 20 ++----- > arch/riscv/mm/fault.c | 9 +--- > arch/s390/mm/fault.c | 10 ++-- > arch/sh/mm/fault.c | 13 +++-- > arch/sparc/mm/fault_32.c | 5 +- > arch/sparc/mm/fault_64.c | 5 +- > arch/um/kernel/trap.c | 3 +- > arch/unicore32/mm/fault.c | 8 ++- > arch/x86/mm/fault.c | 30 +++++------ > arch/xtensa/mm/fault.c | 5 +- > drivers/gpu/drm/ttm/ttm_bo_vm.c | 12 +++-- > fs/userfaultfd.c | 62 ++++++++++------------ > include/linux/mm.h | 81 ++++++++++++++++++++++++---- > include/linux/sched/signal.h | 14 +++++ > mm/filemap.c | 2 +- > mm/gup.c | 93 +++++++++++++++++++++------------ > mm/hugetlb.c | 17 +++--- > mm/internal.h | 6 +-- > 31 files changed, 281 insertions(+), 240 deletions(-) > > -- > 2.24.1 >