Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220901173516.702122-1-surenb@google.com> <20220901173516.702122-4-surenb@google.com>
 <20220901202239.tnnzlbermiyvkmih@moria.home.lan>
In-Reply-To: <20220901202239.tnnzlbermiyvkmih@moria.home.lan>
From:   Suren Baghdasaryan <surenb@google.com>
Date:   Thu, 1 Sep 2022 16:18:04 -0700
Message-ID: <CAJuCfpFqK+Gfd100C8s8jnJci+UCt9y6dqsn=eqYin6g-VVx6Q@mail.gmail.com>
Subject: Re: [RFC PATCH RESEND 03/28] mm: introduce __find_vma to be used
 without mmap_lock protection
To:     Kent Overstreet <kent.overstreet@linux.dev>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Michel Lespinasse <michel@lespinasse.org>,
        Jerome Glisse <jglisse@google.com>,
        Michal Hocko <mhocko@suse.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Mel Gorman <mgorman@suse.de>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Matthew Wilcox <willy@infradead.org>,
        "Liam R. Howlett" <liam.howlett@oracle.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Laurent Dufour <ldufour@linux.ibm.com>,
        Laurent Dufour <laurent.dufour@fr.ibm.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        Song Liu <songliubraving@fb.com>, Peter Xu <peterx@redhat.com>,
        David Hildenbrand <david@redhat.com>, dhowells@redhat.com,
        Hugh Dickins <hughd@google.com>, bigeasy@linutronix.de,
        David Rientjes <rientjes@google.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Joel Fernandes <joelaf@google.com>,
        Minchan Kim <minchan@google.com>,
        kernel-team <kernel-team@android.com>,
        linux-mm <linux-mm@kvack.org>,
        linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, x86@kernel.org,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Sep 1, 2022 at 1:22 PM Kent Overstreet
<kent.overstreet@linux.dev> wrote:
>
> On Thu, Sep 01, 2022 at 10:34:51AM -0700, Suren Baghdasaryan wrote:
> > Add __find_vma function to be used for VMA lookup under rcu protection.
>
> So it was news to me that the rb tree code can be used for lockless lookups -
> not having looked at lib/rbtree.c in over 10 years :) - I still think it should
> be mentioned in the commit message that that's what you're doing and why it's
> safe, because it's not exactly common knowledge and lockless stuff deserves
> extra scrutiny.
>
> Probably worth a comment, too.

Ack.

>
> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>

Thanks!

>
> --
> To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com.
>