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=-8.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 353F9C38A30 for ; Tue, 21 Apr 2020 00:52:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CCE652072D for ; Tue, 21 Apr 2020 00:52:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tXXBWTHU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CCE652072D 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 49EF68E0008; Mon, 20 Apr 2020 20:52:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 44F858E0003; Mon, 20 Apr 2020 20:52:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 364EC8E0008; Mon, 20 Apr 2020 20:52:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0048.hostedemail.com [216.40.44.48]) by kanga.kvack.org (Postfix) with ESMTP id 1F3278E0003 for ; Mon, 20 Apr 2020 20:52:01 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D4B24181AEF2A for ; Tue, 21 Apr 2020 00:52:00 +0000 (UTC) X-FDA: 76730035200.29.whip15_2ea7e883e2d3d X-HE-Tag: whip15_2ea7e883e2d3d X-Filterd-Recvd-Size: 3987 Received: from mail-yb1-f195.google.com (mail-yb1-f195.google.com [209.85.219.195]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 00:52:00 +0000 (UTC) Received: by mail-yb1-f195.google.com with SMTP id i2so6468285ybk.2 for ; Mon, 20 Apr 2020 17:52:00 -0700 (PDT) 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=NzVEjIhE3G8lvkyzAwCPpB3DMUYR5E+cR65yZNSQbxc=; b=tXXBWTHU+2qNp9K4xs2Ulr+LHFl6T2MeUb2ilsTIF1Z72AADbToaiIyMqNr0KwUVxk u6EvbZSc8mCoVUXlTEVkVN+U7Qa3ceu1tQUD77MTZUK0UbRVGeApyRGTKG5xPAqpfQL+ oE3ANckoo6XeBV78XCLsQeDJE/PiyxzS5vAkiBSi4bfMiOqVU8IjAfd4VGzEedxJqnGW haC221Mr4P0tqgQokgCAIsS+iXqX97pnmTLfVlPIVJKK1SPOGiSSfCylJIjCdOlwSHSX k28nvoZ+zQGUl0hlqy2x3si0WSSh+uNJiWEM8Qx/vp3NtdqZTl5omyKqKSXxoZiBxuWb y84Q== 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=NzVEjIhE3G8lvkyzAwCPpB3DMUYR5E+cR65yZNSQbxc=; b=EVdU7tm8bjaG1pR2FVXcv3/AFN8BBvvDDzJFKnQbdmmB0O8q8zgqKYB436rtWgY0GN Nz94SG+IRxFzIdEpGgzlSQYxvxC3EG478nhwGa6Dt0P8H8qq/GulzUDotw3hQBqfiHwg 6kIdt4HGWjTZifrOp7YSBMZD/N4JOz4IJaGKm2fn8xiIqnrSwMbb+2/qfITf/zNhYif2 MO7TgTrfKsMhFNhUR//iRKC6JOO/371agvaR9/5BWa+ujgIjJ8RRrMu7snlp0wHlamFK jYWaasW6pOdSWDqV7TSPBvggb+YW9gQanvYCRkCmlwts0zNaC/zrbzD6GJCyMId13ztv jfdA== X-Gm-Message-State: AGi0PubSs2noHCoc1wuk42TKwCIWV2pItfAcf0muvpv/LjF/rx9nUlok pQZXR+56eqoobjOCjqAh15OE4ZYSuunuZ1K2Qul0mQ== X-Google-Smtp-Source: APiQypI2k2dh6JVBflHjutO4XGPb5dcGoF3tBdky35qHOVENePPd/Bjq4BAYpRTFPx6qgQKk6qchd7f97Pq6xebk/GM= X-Received: by 2002:a25:13ca:: with SMTP id 193mr20028377ybt.320.1587430319630; Mon, 20 Apr 2020 17:51:59 -0700 (PDT) MIME-Version: 1.0 References: <20200415004353.130248-1-walken@google.com> <20200415004353.130248-7-walken@google.com> <20200420193310.GF5820@bombadil.infradead.org> In-Reply-To: <20200420193310.GF5820@bombadil.infradead.org> From: Michel Lespinasse Date: Mon, 20 Apr 2020 17:51:47 -0700 Message-ID: Subject: Re: [PATCH v4 06/10] mmap locking API: convert nested write lock sites To: Matthew Wilcox Cc: Andrew Morton , linux-mm , LKML , Peter Zijlstra , Laurent Dufour , Vlastimil Babka , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan 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: On Mon, Apr 20, 2020 at 12:33 PM Matthew Wilcox wrote: > > On Tue, Apr 14, 2020 at 05:43:49PM -0700, Michel Lespinasse wrote: > > @@ -47,7 +48,7 @@ static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) > > * when the new ->mm is used for the first time. > > */ > > __switch_mm(&new->context.id); > > - down_write_nested(&new->mmap_sem, 1); > > + mmap_write_lock_nested(new, 1); > > This should have already been using SINGLE_DEPTH_NESTING. 1 is > uninformative. Sure, I can change that. Note, all mmap_write_lock_nested call sites use single depth nesting, so I'm not entirely sure if the argument should be passed to mmap_write_lock_nested in the first place ? -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies.