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On Thu, Jul 02, 2020 at 08:25:43PM +1000, Nicholas Piggin wrote: > Excerpts from Will Deacon's message of July 2, 2020 6:02 pm: > > On Thu, Jul 02, 2020 at 05:48:36PM +1000, Nicholas Piggin wrote: > >> diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h > >> new file mode 100644 > >...

On Thu, Jul 02, 2020 at 08:25:43PM +1000, Nicholas Piggin wrote: > Excerpts from Will Deacon's message of July 2, 2020 6:02 pm: > > On Thu, Jul 02, 2020 at 05:48:36PM +1000, Nicholas Piggin wrote: > >> diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h > >> new file mode 100644 > >...

Nicholas Piggin <npiggin at gmail.com> writes: > Signed-off-by: Nicholas Piggin <npiggin at gmail.com> > --- > arch/powerpc/include/asm/paravirt.h | 28 ++++++++ > arch/powerpc/include/asm/qspinlock.h | 66 +++++++++++++++++++ > arch/powerpc/include/asm/qspinlock_par...

Nicholas Piggin <npiggin at gmail.com> writes: > Signed-off-by: Nicholas Piggin <npiggin at gmail.com> > --- > arch/powerpc/include/asm/paravirt.h | 28 ++++++++ > arch/powerpc/include/asm/qspinlock.h | 66 +++++++++++++++++++ > arch/powerpc/include/asm/qspinlock_par...

On Thu, Jul 02, 2020 at 05:48:36PM +1000, Nicholas Piggin wrote: > diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h > new file mode 100644 > index 000000000000..f84da77b6bb7 > --- /dev/null > +++ b/arch/powerpc/include/asm/qspinlock.h > @@ -0,0 +1,20 @@ > +/* SPDX-License-Identifier: GPL-2.0 */...

On Thu, Jul 02, 2020 at 05:48:36PM +1000, Nicholas Piggin wrote: > diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h > new file mode 100644 > index 000000000000..f84da77b6bb7 > --- /dev/null > +++ b/arch/powerpc/include/asm/qspinlock.h > @@ -0,0 +1,20 @@ > +/* SPDX-License-Identifier: GPL-2.0 */...

Nicholas Piggin <npiggin at gmail.com> writes: > These have shown significantly improved performance and fairness when > spinlock contention is moderate to high on very large systems. > > [ Numbers hopefully forthcoming after more testing, but initial > results look good ] Would be good t...

In 2.4.20-pre5 an optimisation was made to the ext3 fsync function which can very easily cause file data corruption at unmount time. This was first reported by Nick Piggin on November 29th (one day after 2.4.20 was released, and three months after the bug was merged. Unfortunate timing) This only affects filesystems which were mounted with the `data=journal' option. Or files which are operating under `chattr -j'. So most people are unaffected. The proble...

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt qspinlocks...

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt qspinlocks...

Signed-off-by: Nick Piggin <npiggin@suse.de> -- Index: linux-2.6/fs/btrfs/compression.c =================================================================== --- linux-2.6.orig/fs/btrfs/compression.c +++ linux-2.6/fs/btrfs/compression.c @@ -478,7 +478,7 @@ static noinline int add_ra_bio_pages(str goto next; } -...

Excerpts from Waiman Long's message of July 8, 2020 1:33 pm: > On 7/7/20 1:57 AM, Nicholas Piggin wrote: >> Yes, powerpc could certainly get more performance out of the slow >> paths, and then there are a few parameters to tune. >> >> We don't have a good alternate patching for function calls yet, but >> that would be something to do for native vs pv. >>...

Excerpts from Waiman Long's message of July 8, 2020 1:33 pm: > On 7/7/20 1:57 AM, Nicholas Piggin wrote: >> Yes, powerpc could certainly get more performance out of the slow >> paths, and then there are a few parameters to tune. >> >> We don't have a good alternate patching for function calls yet, but >> that would be something to do for native vs pv. >>...

On 7/3/20 3:35 AM, Nicholas Piggin wrote: > Signed-off-by: Nicholas Piggin <npiggin at gmail.com> > --- > arch/powerpc/include/asm/paravirt.h | 28 ++++++++++ > arch/powerpc/include/asm/qspinlock.h | 55 +++++++++++++++++++ > arch/powerpc/include/asm/qspinlock_paravirt.h | 5 ++ > arc...

This patch is ported one from 534:77db69c38249 of linux-2.6.18-xen.hg. Use wmb instead of rmb to enforce ordering between evtchn_upcall_pending and evtchn_pending_sel stores in xen_evtchn_do_upcall(). Cc: Samuel Thibault <samuel.thibault at eu.citrix.com> Signed-off-by: Isaku Yamahata <yamahata at valinux.co.jp> --- drivers/xen/events.c | 2 +- 1 files changed, 1 insertions(+), 1

Excerpts from Waiman Long's message of July 7, 2020 4:39 am: > On 7/6/20 12:35 AM, Nicholas Piggin wrote: >> v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). >> >> Thanks, >> Nick >> >> Nicholas Piggin (6): >> powerpc/powernv: must include hvcall.h to get PAPR defines >> powerpc/pseries: move some PAPR paravirt fun...

Excerpts from Waiman Long's message of July 7, 2020 4:39 am: > On 7/6/20 12:35 AM, Nicholas Piggin wrote: >> v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). >> >> Thanks, >> Nick >> >> Nicholas Piggin (6): >> powerpc/powernv: must include hvcall.h to get PAPR defines >> powerpc/pseries: move some PAPR paravirt fun...

On 7/8/20 4:41 AM, Peter Zijlstra wrote: > On Tue, Jul 07, 2020 at 03:57:06PM +1000, Nicholas Piggin wrote: >> Yes, powerpc could certainly get more performance out of the slow >> paths, and then there are a few parameters to tune. > Can you clarify? The slow path is already in use on ARM64 which is weak, > so I doubt there's superfluous serialization present. And Will spend...

On 7/8/20 4:41 AM, Peter Zijlstra wrote: > On Tue, Jul 07, 2020 at 03:57:06PM +1000, Nicholas Piggin wrote: >> Yes, powerpc could certainly get more performance out of the slow >> paths, and then there are a few parameters to tune. > Can you clarify? The slow path is already in use on ARM64 which is weak, > so I doubt there's superfluous serialization present. And Will spend...

Excerpts from Waiman Long's message of July 22, 2020 12:36 am: > On 7/21/20 7:08 AM, Nicholas Piggin wrote: >> diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h >> index b752d34517b3..26d8766a1106 100644 >> --- a/arch/powerpc/include/asm/qspinlock.h >> +++ b/arch/powerpc/include/asm/qspinlock.h >> @@ -31,16 +31,57 @@ static inlin...