From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Byungchul Park <byungchul.park@lge.com>,
Bart Van Assche <Bart.VanAssche@wdc.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"axboe@kernel.dk" <axboe@kernel.dk>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"sfr@canb.auug.org.au" <sfr@canb.auug.org.au>,
"linux-next@vger.kernel.org" <linux-next@vger.kernel.org>,
kernel-team@lge.com
Subject: Re: possible circular locking dependency detected [was: linux-next: Tree for Aug 22]
Date: Wed, 30 Aug 2017 21:30:07 +0900 [thread overview]
Message-ID: <20170830123007.GA6460@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20170830084746.GC660@worktop.programming.kicks-ass.net>
Hello Peter,
On (08/30/17 10:47), Peter Zijlstra wrote:
[..]
> On Wed, Aug 30, 2017 at 10:42:07AM +0200, Peter Zijlstra wrote:
> >
> > So the overhead looks to be spread out over all sorts, which makes it
> > harder to find and fix.
> >
> > stack unwinding is done lots and is fairly expensive, I've not yet
> > checked if crossrelease does too much of that.
>
> Aah, we do an unconditional stack unwind for every __lock_acquire() now.
> It keeps a trace in the xhlocks[].
>
> Does the below cure most of that overhead?
thanks.
mostly yes. the kernel is not so dramatically slower now. it's still
seems to be a bit slower, which is expected I suppose, but over all
it's much better
real 1m35.209s
user 4m12.467s
sys 0m49.457s
// approx 10 seconds slower.
-ss
next prev parent reply other threads:[~2017-08-30 12:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-22 8:38 linux-next: Tree for Aug 22 Stephen Rothwell
2017-08-22 10:47 ` possible circular locking dependency detected [was: linux-next: Tree for Aug 22] Sergey Senozhatsky
2017-08-22 21:43 ` Bart Van Assche
2017-08-23 0:03 ` Byungchul Park
2017-08-23 2:36 ` Sergey Senozhatsky
2017-08-23 2:59 ` Byungchul Park
2017-08-23 3:49 ` Boqun Feng
2017-08-23 4:38 ` Boqun Feng
2017-08-23 4:46 ` Sergey Senozhatsky
2017-08-23 5:35 ` Boqun Feng
2017-08-23 5:44 ` Sergey Senozhatsky
2017-08-23 5:55 ` Sergey Senozhatsky
2017-08-24 4:39 ` Boqun Feng
2017-08-24 4:49 ` Sergey Senozhatsky
2017-08-23 5:44 ` Byungchul Park
2017-08-23 4:46 ` Byungchul Park
2017-08-23 5:01 ` Boqun Feng
2017-08-23 7:53 ` Peter Zijlstra
2017-08-30 5:20 ` Sergey Senozhatsky
2017-08-30 5:43 ` Byungchul Park
2017-08-30 6:15 ` Sergey Senozhatsky
2017-08-30 8:42 ` Peter Zijlstra
2017-08-30 8:47 ` Peter Zijlstra
2017-08-30 8:53 ` Byungchul Park
2017-08-30 12:30 ` Sergey Senozhatsky [this message]
2017-08-22 18:11 ` linux-next: Tree for Aug 22 Stephen Rothwell
2017-08-22 18:14 ` Stephen Rothwell
2017-08-22 18:59 ` Paul E. McKenney
2017-08-22 19:12 ` Stephen Rothwell
2017-08-22 19:32 ` Paul E. McKenney
2017-08-22 19:36 ` Paul E. McKenney
2017-08-22 21:57 ` Stephen Rothwell
2017-08-22 22:27 ` Stephen Rothwell
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