From: Nicholas Piggin <npiggin@gmail.com>
To: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 10/14] powerpc/64s: cpuidle set polling before enabling irqs
Date: Tue, 13 Jun 2017 01:20:06 +1000 [thread overview]
Message-ID: <20170613012006.387e19d5@roar.ozlabs.ibm.com> (raw)
In-Reply-To: <20170612151025.GG10921@in.ibm.com>
On Mon, 12 Jun 2017 20:40:25 +0530
Gautham R Shenoy <ego@linux.vnet.ibm.com> wrote:
> On Mon, Jun 12, 2017 at 09:58:31AM +1000, Nicholas Piggin wrote:
> > local_irq_enable can cause interrupts to be taken which could
> > take significant amount of processing time. The idle process
> > should set its polling flag before this, so another process that
> > wakes it during this time will not have to send an IPI.
> >
> > Expand the TIF_POLLING_NRFLAG coverage to as large as possible.
> >
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>
> Looks good. Were you able to see this make a difference in any of the
> tests ?
No I didn't measure a difference or have a test case where this was
noticable. I think on a workload with some IO interrupts as well as
cross-CPU wakeups, then statistically we should see some improvement
in IPI rates with this patch.
Thanks,
Nick
next prev parent reply other threads:[~2017-06-12 15:20 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-11 23:58 [PATCH 00/14 v2] idle performance improvements Nicholas Piggin
2017-06-11 23:58 ` [PATCH 01/14] powerpc/64s: idle move soft interrupt mask logic into C code Nicholas Piggin
2017-06-12 8:37 ` Gautham R Shenoy
2017-06-12 14:46 ` Nicholas Piggin
2017-06-13 4:28 ` Gautham R Shenoy
2017-06-11 23:58 ` [PATCH 02/14] powerpc/64s: idle hotplug lazy-irq simplification Nicholas Piggin
2017-06-11 23:58 ` [PATCH 03/14] powerpc/64s: idle provide a default idle for POWER9 Nicholas Piggin
2017-06-12 8:53 ` Gautham R Shenoy
2017-06-12 14:46 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 04/14] powerpc/64s: idle process interrupts from system reset wakeup Nicholas Piggin
2017-06-12 9:41 ` Gautham R Shenoy
2017-06-12 14:51 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions Nicholas Piggin
2017-06-12 14:38 ` Gautham R Shenoy
2017-06-11 23:58 ` [PATCH 06/14] powerpc/64s: interrupt replay balance the return branch predictor Nicholas Piggin
2017-06-12 14:41 ` Gautham R Shenoy
2017-06-13 9:51 ` Michael Ellerman
2017-06-13 11:09 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 07/14] powerpc/64s: idle branch to handler with virtual mode offset Nicholas Piggin
2017-06-11 23:58 ` [PATCH 08/14] powerpc/64s: idle avoid SRR usage in idle sleep/wake paths Nicholas Piggin
2017-06-13 10:25 ` Gautham R Shenoy
2017-06-13 10:45 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 09/14] powerpc/64s: idle hmi wakeup is unlikely Nicholas Piggin
2017-06-12 15:03 ` Gautham R Shenoy
2017-06-11 23:58 ` [PATCH 10/14] powerpc/64s: cpuidle set polling before enabling irqs Nicholas Piggin
2017-06-12 15:10 ` Gautham R Shenoy
2017-06-12 15:20 ` Nicholas Piggin [this message]
2017-06-11 23:58 ` [PATCH 11/14] powerpc/64s: cpuidle read mostly for common globals Nicholas Piggin
2017-06-12 15:30 ` Gautham R Shenoy
2017-06-12 17:50 ` Vaidyanathan Srinivasan
2017-06-11 23:58 ` [PATCH 12/14] powerpc/64s: cpuidle no memory barrier after break from idle Nicholas Piggin
2017-06-12 17:48 ` Vaidyanathan Srinivasan
2017-06-13 12:47 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 13/14] powerpc/64: runlatch CTRL[RUN] set optimisation Nicholas Piggin
2017-06-12 17:11 ` Vaidyanathan Srinivasan
2017-06-13 10:04 ` Michael Ellerman
2017-06-13 11:56 ` Nicholas Piggin
2017-06-13 13:45 ` Benjamin Herrenschmidt
2017-06-14 3:34 ` Michael Ellerman
2017-06-11 23:58 ` [PATCH 14/14] powerpc/64s: idle runlatch switch is done with MSR[EE]=0 Nicholas Piggin
2017-06-12 17:00 ` Vaidyanathan Srinivasan
-- strict thread matches above, loose matches on Subject: below --
2017-06-08 15:50 [PATCH 00/14] idle performance improvements Nicholas Piggin
2017-06-08 15:51 ` [PATCH 10/14] powerpc/64s: cpuidle set polling before enabling irqs Nicholas Piggin
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