Date: Thu, 17 May 2018 10:07:34 -0700 From: Conrad Meyer <cem@freebsd.org> To: Mark Johnston <markj@freebsd.org> Cc: src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r333703 - head/sys/vm Message-ID: <CAG6CVpWpQgJOyXpN3z%2B7xBu2%2BQ_gRvXDfhVLvrKfUp7EgFzvDQ@mail.gmail.com> In-Reply-To: <201805170427.w4H4R8lv058775@repo.freebsd.org> References: <201805170427.w4H4R8lv058775@repo.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, May 16, 2018 at 9:27 PM, Mark Johnston <markj@freebsd.org> wrote: > Author: markj > Date: Thu May 17 04:27:08 2018 > New Revision: 333703 > URL: https://svnweb.freebsd.org/changeset/base/333703 > > Log: > Fix a race in vm_page_pagequeue_lockptr(). > > The value of m->queue must be cached after comparing it with PQ_NONE, > since it may be concurrently changing. > > Reported by: glebius What were the symptoms of this issue? The test plan in the linked phabricator revision says: "Gleb reported seeing panics as a result of the use of a bogus index into the pagequeue array, and also reported that this patch fixed the panics." So an attempt to lock pagequeues[PQ_NONE=255].pq_mutex, which is either something later in the vm_domain object, or bogus memory? One of the mtx asserts trips? Thanks, Conrad
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAG6CVpWpQgJOyXpN3z%2B7xBu2%2BQ_gRvXDfhVLvrKfUp7EgFzvDQ>