Date: Wed, 19 Apr 2017 06:22:28 +0200 From: Hans Petter Selasky <hps@selasky.org> To: Sepherosa Ziehau <sepherosa@gmail.com>, "Somayajulu, David" <David.Somayajulu@cavium.com> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Re: Question on taskqueue_drain Message-ID: <1fb80f2b-9086-0260-2f63-bdaf8afc1c4c@selasky.org> In-Reply-To: <CAMOc5cxtSakeBhskbmfW4BxsbgdRDp22AVBYrDgReCP91YLY7g@mail.gmail.com> References: <BY2PR07MB14745123AC235B06BCD2987DEE190@BY2PR07MB1474.namprd07.prod.outlook.com> <BY2PR07MB1474C78A241A7CA1F2396435EE180@BY2PR07MB1474.namprd07.prod.outlook.com> <CAMOc5cxtSakeBhskbmfW4BxsbgdRDp22AVBYrDgReCP91YLY7g@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 04/19/17 05:37, Sepherosa Ziehau wrote: > On Wed, Apr 19, 2017 at 10:39 AM, Somayajulu, David > <David.Somayajulu@cavium.com> wrote: >> Sorry what I meant to ask was, whether it is O.K to call taskqueue_drain(), when an MTX_DEF lock is grabbed prior to calling taskqueue_drain(). >> > > You will hit WITNESS, if the drain needs to wait; that's probably the > best case. If the lock will be acquired in the task being drained, > this leads to deadlock. > Hi, No sleeping functions like taskqueue_drain() can be called when the MTX_DEF lock is grabbed. --HPS
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1fb80f2b-9086-0260-2f63-bdaf8afc1c4c>