On Wed, Aug 30, 2017 at 8:25 PM, Byungchul Park <byungchul.p...@lge.com> wrote: > On Wed, Aug 30, 2017 at 06:24:39PM +0900, Byungchul Park wrote: >> > -----Original Message----- >> > From: Peter Zijlstra [mailto:pet...@infradead.org] >> > Sent: Wednesday, August 30, 2017 6:12 PM >> > To: Byungchul Park >> > Cc: mi...@kernel.org; t...@kernel.org; boqun.f...@gmail.com; >> > da...@fromorbit.com; johan...@sipsolutions.net; o...@redhat.com; linux- >> > ker...@vger.kernel.org; kernel-t...@lge.com >> > Subject: Re: [PATCH 4/4] lockdep: Fix workqueue crossrelease annotation >> > >> > On Wed, Aug 30, 2017 at 06:01:59PM +0900, Byungchul Park wrote: >> > > My point is that we inevitably lose valuable dependencies by yours. >> > That's >> > > why I've endlessly asked you 'do you have any reason you try those >> > patches?' >> > > a ton of times. And you have never answered it. >> > >> > The only dependencies that are lost are those between the first work and >> > the setup of the workqueue thread. >> > >> > And there obviously _should_ not be any dependencies between those. A >> >> 100% right. Since there obviously should not be any, it would be better >> to check them. So I've endlessly asked you 'do you have any reason removing >> the opportunity for that check?'. Overhead? Logical problem? Or want to >> believe workqueue setup code perfect forever? I mean, is it a problem if we >> check them? >> >> > work should not depend on the setup of the thread. >> >> 100% right. > > For example - I'm giving you the same example repeatedly: > > context X context Y > --------- --------- > wait_for_completion(C) > acquire(A) > process_one_work() > acquire(B) > work->fn() > complete(C) > > Please check C->A and C->B.
s/check/let lockdep check/ -- Thanks, Byungchul
