Re: [RFC PATCH v2] memory-barriers: remove smp_mb__after_unlock_lock()

From	Michael Ellerman <mpe@ellerman.id.au>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH v2] memory-barriers: remove smp_mb__after_unlock_lock()
Date	2015-07-16 03:40 +0200
Message-ID	<pMGjv-dw-3@gated-at.bofh.it> (permalink)
References	<pLKSf-4Ui-47@gated-at.bofh.it> <pLUyd-2Au-5@gated-at.bofh.it> <pMlf3-3in-5@gated-at.bofh.it> <pMvHs-1uR-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, 2015-07-15 at 07:18 -0700, Paul E. McKenney wrote:
> On Wed, Jul 15, 2015 at 01:06:18PM +1000, Michael Ellerman wrote:
> > On Tue, 2015-07-14 at 08:31 +1000, Benjamin Herrenschmidt wrote:
> > > Michael, at some point you were experimenting a bit with that and tried
> > > to get some perf numbers of the impact that would have, did that
> > > solidify ? Otherwise, I'll have a look when I'm back next week.
> > 
> > I was mainly experimenting with replacing the lwsync in lock with an isync.
> > 
> > But I think you're talking about making it a full sync in lock.
> > 
> > That was about +7% on p8, +25% on p7 and +88% on p6.
> 
> Just for completeness, what were you running as benchmark?  ;-)

Heh sorry :)

That was my lockcomparison benchmark, based on Anton's original. It just does
100,000,000 lock/unlocks for each type in userspace:

  https://github.com/mpe/lockcomparison/blob/master/lock_comparison.c

cheers


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[RFC PATCH v2] memory-barriers: remove smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-13 14:20 +0200
  Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Peter Zijlstra <peterz@infradead.org> - 2015-07-14 10:40 +0200
  Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-14 12:10 +0200
    Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-14 21:40 +0200
      Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-15 03:40 +0200
        Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-15 13:00 +0200
          Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-15 15:20 +0200
  Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Michael Ellerman <mpe@ellerman.id.au> - 2015-07-15 05:10 +0200
    Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-15 12:50 +0200
      Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Michael Ellerman <mpe@ellerman.id.au> - 2015-07-16 04:10 +0200
        Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-16 17:20 +0200
          Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Benjamin Herrenschmidt <benh@kernel.crashing.org> - 2015-07-17 01:00 +0200
            Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-17 11:40 +0200
              Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Peter Zijlstra <peterz@infradead.org> - 2015-07-17 12:20 +0200
                Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-17 14:50 +0200
              Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Benjamin Herrenschmidt <benh@kernel.crashing.org> - 2015-07-18 00:20 +0200
                Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-20 15:40 +0200
                Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-20 15:50 +0200
                Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Will Deacon <will.deacon@arm.com> - 2015-07-20 16:00 +0200
    Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-07-15 16:20 +0200
      Re: [RFC PATCH v2] memory-barriers: remove  smp_mb__after_unlock_lock() Michael Ellerman <mpe@ellerman.id.au> - 2015-07-16 03:40 +0200

csiph-web