Date: Mon, 22 Oct 2018 13:20:16 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Hans Petter Selasky <hps@selasky.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r339582 - head/sys/dev/sound/midi Message-ID: <20181022102016.GO5335@kib.kiev.ua> In-Reply-To: <cc0210c5-99c7-1153-0b32-4cfdc576970a@selasky.org> References: <201810220858.w9M8wSBZ039042@repo.freebsd.org> <20181022095131.GN5335@kib.kiev.ua> <cc0210c5-99c7-1153-0b32-4cfdc576970a@selasky.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Oct 22, 2018 at 12:09:54PM +0200, Hans Petter Selasky wrote: > On 10/22/18 11:51 AM, Konstantin Belousov wrote: > > On Mon, Oct 22, 2018 at 08:58:28AM +0000, Hans Petter Selasky wrote: > >> Author: hselasky > >> Date: Mon Oct 22 08:58:27 2018 > >> New Revision: 339582 > >> URL: https://svnweb.freebsd.org/changeset/base/339582 > >> > >> Log: > >> Drop sequencer mutex around uiomove() and make sure we don't move more bytes > >> than is available, else a panic might happen. > > And why it is safe to drop the mutex ? > > If it is safe to drop, why do you need the mutex at all ? > > > > The seq mutex protects the queue state, which is entirely computed prior > or after uiomove(). Then why do you need to re-acquire the mutex after uiomove ?
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20181022102016.GO5335>