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Mon, 5 Sep 2022 12:32:00 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id fCGsOkDsFWMtBQAAMHmgww (envelope-from ); Mon, 05 Sep 2022 12:32:00 +0000 Date: Mon, 5 Sep 2022 14:32:00 +0200 From: Michal Hocko To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, michel@lespinasse.org, jglisse@google.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, kernel-team@android.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH RESEND 00/28] per-VMA locks proposal Message-ID: References: <20220901173516.702122-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; 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bh=OxQfDCqBUCjwjZQ5n2rijS/hjypOhZZuZ+okmIcJ/2A=; b=dG8dzuKARydyTqdBeQEWTCAkB9JRd6QSDvmnyDdLdmbF8zte0PNCYG+OCU3D8XB5v0nbsb wvYNHsBjbKN41H5K5q+ohWysus307zsahmX+WhIHOHHzVw7tqzHeAnO8N6DdiISDZHBIOt exlRY89NqQGk1Pt82dYxv5ktvZ5sFys= X-Rspam-User: X-Stat-Signature: 5onryuh64u1gis3cdsdgtz8c6wgid58o X-Rspamd-Queue-Id: 7F7F420065 X-Rspamd-Server: rspam10 Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=AlkQM6um; spf=pass (imf13.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-HE-Tag: 1662381122-477988 X-Bogosity: Ham, tests=bogofilter, spamicity=0.001496, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Unless I am missing something, this is not based on the Maple tree rewrite, right? Does the change in the data structure makes any difference to the approach? I remember discussions at LSFMM where it has been pointed out that some issues with the vma tree are considerably simpler to handle with the maple tree. On Thu 01-09-22 10:34:48, Suren Baghdasaryan wrote: [...] > One notable way the implementation deviates from the proposal is the way > VMAs are marked as locked. Because during some of mm updates multiple > VMAs need to be locked until the end of the update (e.g. vma_merge, > split_vma, etc). I think it would be really helpful to spell out those issues in a greater detail. Not everybody is aware of those vma related subtleties. Thanks for working on this Suren! -- Michal Hocko SUSE Labs