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From: Akemi Yagi <toracat@elrepo.org>
To: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 0/2] pipe: Fixes [ver #2]
Date: Sat, 7 Dec 2019 13:31:13 -0800	[thread overview]
Message-ID: <qsh5n2$3pu9$1@blaine.gmane.org> (raw)
In-Reply-To: <CAHk-=wj9pprDUeoJd5EeN-2x7+GXdSsm44mSv1y9f5e7MrTZ2A@mail.gmail.com>

On 12/6/19 10:59 AM, Linus Torvalds wrote:
> Hmm. I think I just saw this same bug with a plain kernel compile.
> 
> My "make -j32" suddenly came to a crawl, and seems to be entirely
> single-threaded.
> 
> And that's almost certainly because the way 'make' handles load
> distribution is with a network of pipes that has a token passed to the
> sub-makes.
> 
> So there's most definitely something wrong with the new pipe rework.
> Well, I can't _guarantee_ the pipes are the cause of this, but it does
> smell like it.
> 
>                Linus
> 

We encountered what seems to be the same problem when building a kernel
under RHEL 8.

As it turned out, this was due to a bug in make (make-4.2.1-9.el8) and
a patch is available. Details are found in this Red Hat bugzilla report:

https://bugzilla.redhat.com/show_bug.cgi?id=1774790

Akemi


WARNING: multiple messages have this Message-ID (diff)
From: Akemi Yagi <toracat@elrepo.org>
To: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] pipe: Fixes [ver #2]
Date: Sat, 7 Dec 2019 13:31:13 -0800	[thread overview]
Message-ID: <qsh5n2$3pu9$1@blaine.gmane.org> (raw)
In-Reply-To: <CAHk-=wj9pprDUeoJd5EeN-2x7+GXdSsm44mSv1y9f5e7MrTZ2A@mail.gmail.com>

On 12/6/19 10:59 AM, Linus Torvalds wrote:
> Hmm. I think I just saw this same bug with a plain kernel compile.
> 
> My "make -j32" suddenly came to a crawl, and seems to be entirely
> single-threaded.
> 
> And that's almost certainly because the way 'make' handles load
> distribution is with a network of pipes that has a token passed to the
> sub-makes.
> 
> So there's most definitely something wrong with the new pipe rework.
> Well, I can't _guarantee_ the pipes are the cause of this, but it does
> smell like it.
> 
>                Linus
> 

We encountered what seems to be the same problem when building a kernel
under RHEL 8.

As it turned out, this was due to a bug in make (make-4.2.1-9.el8) and
a patch is available. Details are found in this Red Hat bugzilla report:

https://bugzilla.redhat.com/show_bug.cgi?id=1774790

Akemi


  reply	other threads:[~2019-12-07 21:31 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-05 22:30 [PATCH 0/2] pipe: Fixes [ver #2] David Howells
2019-12-05 22:30 ` [PATCH 1/2] pipe: Remove assertion from pipe_poll() " David Howells
2019-12-05 22:30 ` [PATCH 2/2] pipe: Fix missing mask update after pipe_wait() " David Howells
2019-12-05 23:58   ` Linus Torvalds
2019-12-06 13:56 ` [PATCH 0/2] pipe: Fixes " David Sterba
2019-12-06 17:09   ` Linus Torvalds
2019-12-06 17:42     ` Linus Torvalds
2019-12-06 18:59       ` Linus Torvalds
2019-12-07 21:31         ` Akemi Yagi [this message]
2019-12-07 21:31           ` Akemi Yagi
2019-12-08 16:45           ` Akemi Yagi
2019-12-08 18:04             ` Linus Torvalds
2019-12-09  3:07               ` Linus Torvalds
2019-12-06 20:28   ` Linus Torvalds
2019-12-06 21:04     ` Linus Torvalds
2019-12-07  3:50       ` Linus Torvalds
2019-12-07  4:01         ` Linus Torvalds
2019-12-07 22:47         ` Linus Torvalds
2019-12-09  9:53           ` Vincent Guittot
2019-12-09 17:48             ` Linus Torvalds
2019-12-09 17:57               ` Akemi Yagi
2019-12-09 18:18                 ` Linus Torvalds
2019-12-09 18:24                   ` Linus Torvalds
2019-12-18 20:59                   ` Josh Triplett
2019-12-10  2:58               ` DJ Delorie
2019-12-10 14:38               ` Vincent Guittot
2019-12-10 17:39                 ` Linus Torvalds
2019-12-11 18:09               ` DJ Delorie
2019-12-11 18:59                 ` Linus Torvalds
2019-12-12 10:18           ` Konstantin Khlebnikov
2019-12-18 22:51             ` Linus Torvalds
2019-12-19  0:03               ` Josh Triplett
2019-12-19  0:14                 ` Josh Triplett
2019-12-19  0:51                   ` Linus Torvalds
2019-12-19  0:54                     ` Linus Torvalds
2019-12-19  7:56                   ` David Howells
2019-12-19 16:35                     ` Linus Torvalds
2019-12-11 20:55         ` David Howells
2019-12-12  1:28           ` Linus Torvalds
2019-12-12  7:34           ` David Howells
2019-12-09 14:55       ` David Sterba
2019-12-06 21:26   ` David Howells

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