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Groups > linux.kernel > #1678067
| From | Linus Torvalds <torvalds@linux-foundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/4] swait: add the missing killable swaits |
| Date | 2017-06-29 21:00 +0200 |
| Message-ID | <tXMPv-2Ms-3@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <tXHZw-8dW-9@gated-at.bofh.it> <tXKkF-1nd-3@gated-at.bofh.it> <tXLJL-28r-1@gated-at.bofh.it> <tXLTr-2de-3@gated-at.bofh.it> <tXMwa-2FO-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Jun 29, 2017 at 11:33 AM, Davidlohr Bueso <dave@stgolabs.net> wrote:
> On Thu, 29 Jun 2017, Linus Torvalds wrote:
>
>> I actually think swait is pure garbage. Most users only wake up one
>> process anyway, and using swait for that is stupid. If you only wake
>> up one, you might as well just have a single process pointer, not a
>> wait list at all, and then use "wake_up_process()".
>
> But you still need the notion of a queue, even if you wake one task
> 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. If
there are, I don't see why the wake-up-one semantics the code uses
would be valid, though.
Linus
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Re: [PATCH 2/4] swait: add the missing killable swaits Greg KH <gregkh@linuxfoundation.org> - 2017-06-29 15:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Thomas Gleixner <tglx@linutronix.de> - 2017-06-29 15:10 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Greg KH <gregkh@linuxfoundation.org> - 2017-06-29 15:40 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Thomas Gleixner <tglx@linutronix.de> - 2017-06-29 15:50 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-29 18:20 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-06-29 19:30 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Davidlohr Bueso <dave@stgolabs.net> - 2017-06-29 19:50 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-29 20:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Davidlohr Bueso <dave@stgolabs.net> - 2017-06-29 20:40 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-29 21:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-06-29 21:50 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-06-29 21:50 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Jakub Kicinski <jakub.kicinski@netronome.com> - 2017-06-29 23:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Jakub Kicinski <jakub.kicinski@netronome.com> - 2017-06-30 01:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Jakub Kicinski <jakub.kicinski@netronome.com> - 2017-06-30 01:10 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-06-30 01:10 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-06-30 01:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-29 23:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Marcelo Tosatti <mtosatti@redhat.com> - 2017-06-30 04:40 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Linus Torvalds <torvalds@linux-foundation.org> - 2017-06-30 06:10 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Marcelo Tosatti <mtosatti@redhat.com> - 2017-06-30 14:00 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Marcelo Tosatti <mtosatti@redhat.com> - 2017-06-30 14:10 +0200
Re: [PATCH 2/4] swait: add the missing killable swaits Krister Johansen <kjlx@templeofstupid.com> - 2017-06-30 19:40 +0200
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