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From: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
To: "Luis R. Rodriguez" <mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Davidlohr Bueso <dave-h16yJtLeMjHk1uMJSBkQmQ@public.gmane.org>,
	Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>,
	Greg KH
	<gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>,
	mfuzzey-mB3Nsq4MPf1BDgjK7y7TUQ@public.gmane.org,
	"Eric W. Biederman"
	<ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>,
	Dmitry Torokhov
	<dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Daniel Wagner <wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>,
	David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	jewalt-d4N2ExZK1jaSe5ORCPIMD9BPR1lH4CV8@public.gmane.org,
	rafal-g1n6cQUeyibVItvQsEIGlw@public.gmane.org,
	Arend Van Spriel
	<arend.vanspriel-dY08KVG/lbpWk0Htik3J/w@public.gmane.org>,
	"Rafael J. Wysocki" <rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org>,
	"Li, Yi" <yi1.li-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	atull-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	Moritz Fischer
	<moritz.fischer-+aYTwkv1SeIAvxtiuMwx3w@public.gmane.org>,
	Petr Mladek <pmladek-IBi9RG/b67k@public.gmane.org>,
	Johannes Berg
	<johannes.berg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Emmanuel Grumbach
	<emmanuel.grumbach-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	"Coelho,
	Luciano" <luciano.coelho-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Kalle Valo <kvalo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	Andrew Lutomirski <luto@kernel.>
Subject: Re: [PATCH 2/4] swait: add the missing killable swaits
Date: Thu, 29 Jun 2017 13:57:41 -0700	[thread overview]
Message-ID: <CA+55aFyCMha0Q1=wRFP-Xa93SHvr97sa1bzJDsx0m3=GyiqADw@mail.gmail.com> (raw)
In-Reply-To: <20170629194015.GQ21846-B4tOwbsTzaBolqkO4TVVkw@public.gmane.org>

On Thu, Jun 29, 2017 at 12:40 PM, Luis R. Rodriguez <mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> On Thu, Jun 29, 2017 at 11:59:29AM -0700, Linus Torvalds wrote:
>> > at a time... I'm probably missing your point here.
>>
>> The *reason* they wake up only one seems to be that there really is
>> just one. It's some per-cpu idle thread for kvm, and for RCU it's the
>> RCU workqueue thread.
>>
>> So the queue literally looks suspiciously pointless.
>>
>> But I might be wrong, and there can actually be multiple entries.
>
> Since this swake_up() --> swake_up_all() reportedly *fixed* the one wake up
> issue it would seem this does queue [0].

I'm not talking about the firmware code.

That thing never had an excuse to use swait in the first place.

I'm talking about kvm and rcu, which *do* have excuses to use it, but
where I argue that swait is _still_ a questionable interface for other
reasons.

                Linus

  parent reply	other threads:[~2017-06-29 20:57 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-14 22:20 [PATCH 0/4] firmware: fix fallback mechanism by ignoring SIGCHLD Luis R. Rodriguez
2017-06-14 22:20 ` [PATCH 1/4] test_firmware: add test case for SIGCHLD on sync fallback Luis R. Rodriguez
2017-06-14 22:20 ` [PATCH 2/4] swait: add the missing killable swaits Luis R. Rodriguez
     [not found]   ` <20170614222017.14653-3-mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2017-06-29 12:54     ` Greg KH
     [not found]       ` <20170629125402.GH26046-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2017-06-29 13:05         ` Thomas Gleixner
2017-06-29 13:35           ` Greg KH
2017-06-29 13:46             ` Thomas Gleixner
2017-06-29 16:13               ` Linus Torvalds
2017-06-29 16:31                 ` Matthew Wilcox
2017-06-29 17:29                   ` Luis R. Rodriguez
2017-06-29 17:40                 ` Davidlohr Bueso
2017-06-29 17:57                   ` Linus Torvalds
2017-06-29 18:33                     ` Davidlohr Bueso
     [not found]                       ` <20170629183339.GD3954-3dK4OQgjB4rH06JGZaSw0A@public.gmane.org>
2017-06-29 18:59                         ` Linus Torvalds
     [not found]                           ` <CA+55aFz8Mhx+A-g-5yOG-O1ZLRUR_fpeeA4iBNGH8EnDBZEdpA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-06-29 19:40                             ` Luis R. Rodriguez
2017-06-29 19:44                               ` Luis R. Rodriguez
     [not found]                                 ` <20170629194455.GR21846-B4tOwbsTzaBolqkO4TVVkw@public.gmane.org>
2017-06-29 20:58                                   ` Jakub Kicinski
2017-06-29 22:50                                     ` Luis R. Rodriguez
2017-06-29 22:53                                       ` Jakub Kicinski
2017-06-29 23:00                                         ` Luis R. Rodriguez
2017-06-29 23:06                                           ` Jakub Kicinski
     [not found]                                       ` <20170629225003.GU21846-B4tOwbsTzaBolqkO4TVVkw@public.gmane.org>
2017-07-12 21:33                                         ` Luis R. Rodriguez
     [not found]                               ` <20170629194015.GQ21846-B4tOwbsTzaBolqkO4TVVkw@public.gmane.org>
2017-06-29 20:57                                 ` Linus Torvalds [this message]
2017-07-05  2:06                       ` Davidlohr Bueso
     [not found]                         ` <20170705020635.GD11168-3dK4OQgjB4rH06JGZaSw0A@public.gmane.org>
2017-07-07 19:58                           ` Linus Torvalds
2017-07-07 22:27                             ` Davidlohr Bueso
2017-07-07 22:48                               ` Linus Torvalds
2017-06-29 19:15                 ` Marcelo Tosatti
     [not found]                   ` <20170629191506.GB12368-I4X2Mt4zSy4@public.gmane.org>
2017-06-30  4:03                     ` Linus Torvalds
2017-06-30 11:55                       ` Marcelo Tosatti
2017-06-30 11:57                       ` Marcelo Tosatti
2017-06-30 17:30                       ` Krister Johansen
2017-06-14 22:20 ` [PATCH 3/4] firmware: avoid invalid fallback aborts by using killable swait Luis R. Rodriguez
2017-06-14 22:20 ` [PATCH 4/4] firmware: send -EINTR on signal abort on fallback mechanism Luis R. Rodriguez
2017-06-15  7:49 ` [PATCH 0/4] firmware: fix fallback mechanism by ignoring SIGCHLD Martin Fuzzey
     [not found] ` <20170614222017.14653-1-mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2017-06-26 21:19   ` Luis R. Rodriguez
2017-06-29 15:14   ` Greg KH
     [not found]     ` <20170629151442.GA4880-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2017-06-29 17:29       ` Luis R. Rodriguez

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