From: David Gibson <david@gibson.dropbear.id.au>
To: Daniel Henrique Barboza <danielhb413@gmail.com>
Cc: gustavo.romero@linaro.org, clg@kaod.org, qemu-ppc@nongnu.org,
qemu-devel@nongnu.org, groug@kaod.org
Subject: Re: [PATCH 18/19] target/ppc/pmu_book3s_helper.c: add PM_CMPLU_STALL mock events
Date: Wed, 11 Aug 2021 13:37:28 +1000 [thread overview]
Message-ID: <YRNF+PyU22DNatBa@yekko> (raw)
In-Reply-To: <79d98671-0da4-bc89-aa7d-a6778e0af4da@gmail.com>
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On Tue, Aug 10, 2021 at 04:48:59PM -0300, Daniel Henrique Barboza wrote:
>
>
> On 8/10/21 1:17 AM, David Gibson wrote:
> > On Mon, Aug 09, 2021 at 10:10:56AM -0300, Daniel Henrique Barboza wrote:
> > > EBB powerpc kernel test 'multi_counter_test' uses PM_CMPLU_STALL events
> > > that we do not support. These events are related to CPU stalled/wasted
> > > cycles while waiting for resources, cache misses and so on.
> > >
> > > Unlike the 0xFA event added previously, there's no available equivalent
> > > for us to use, and at this moment we can't sample those events as well.
> > > What we can do is mock those events as if we were calculating them.
> > >
> > > This patch implements PM_CMPLU_STALL, PM_CMPLU_STALL_FXU,
> > > PM_CMPLU_STALL_OTHER_CMPL and PM_CMPLU_STALL_THRD mock events by giving
> > > them a fixed amount of the total elapsed cycles.
> > >
> > > The chosen sample values for these events (25% of total cycles for
> > > PM_CMPLU_STALL and 5% for the other three) were chosen at random and has
> > > no intention of being truthful with what a real PowerPC hardware would
> > > give us. Our intention here is to make 'multi_counter_test' EBB test
> > > pass.
> >
> > Hmm. I guess these mock values make sense for getting the kernel
> > tests to pass, but I'm not sure if it's a good idea in general. Would
> > we be better off just reporting 0 always - that would be a strong hint
> > to someone attempting to analyze results that something is fishy (in
> > this case that they don't actually have a real CPU).
>
> We can drop this patch and I'll add a note in the docs that the EBB kernel
> test 'multi_counter_test' fails because the PMU does not implement STALL
> events.
Sounds good for now. We can reconsider this if we have a specific
justification for it.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2021-08-11 6:58 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 13:10 [PATCH 00/19] PMU-EBB support for PPC64 TCG Daniel Henrique Barboza
2021-08-09 13:10 ` [PATCH 01/19] target/ppc: add exclusive Book3S PMU reg read/write functions Daniel Henrique Barboza
2021-08-10 3:19 ` David Gibson
2021-08-10 13:06 ` Daniel Henrique Barboza
2021-08-09 13:10 ` [PATCH 02/19] target/ppc: add exclusive user read function for PMU regs Daniel Henrique Barboza
2021-08-10 3:21 ` David Gibson
2021-08-09 13:10 ` [PATCH 03/19] target/ppc: add exclusive user write " Daniel Henrique Barboza
2021-08-10 3:29 ` David Gibson
2021-08-11 0:05 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 04/19] target/ppc: PMU Book3s basic insns count for pseries TCG Daniel Henrique Barboza
2021-08-10 3:39 ` David Gibson
2021-08-10 13:24 ` Daniel Henrique Barboza
2021-08-16 17:53 ` Daniel Henrique Barboza
2021-08-17 2:59 ` David Gibson
2021-08-17 9:30 ` Daniel Henrique Barboza
2021-08-18 5:48 ` David Gibson
2021-08-11 0:26 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 05/19] target/ppc/pmu_book3s_helper.c: eliminate code repetition Daniel Henrique Barboza
2021-08-10 3:40 ` David Gibson
2021-08-09 13:10 ` [PATCH 06/19] target/ppc/pmu_book3s_helper: enable PMC1-PMC4 events Daniel Henrique Barboza
2021-08-10 3:42 ` David Gibson
2021-08-10 15:03 ` Daniel Henrique Barboza
2021-08-10 23:08 ` Daniel Henrique Barboza
2021-08-11 23:27 ` Daniel Henrique Barboza
2021-08-12 1:52 ` David Gibson
2021-08-11 3:32 ` David Gibson
2021-08-09 13:10 ` [PATCH 07/19] target/ppc/pmu_book3s_helper.c: icount fine tuning Daniel Henrique Barboza
2021-08-09 13:10 ` [PATCH 08/19] target/ppc/pmu_book3s_helper.c: do an actual cycles calculation Daniel Henrique Barboza
2021-08-11 0:34 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 09/19] PPC64/TCG: Implement 'rfebb' instruction Daniel Henrique Barboza
2021-08-10 3:50 ` David Gibson
2021-08-10 19:32 ` Daniel Henrique Barboza
2021-08-11 0:42 ` Richard Henderson
2021-08-11 3:36 ` David Gibson
2021-08-11 0:41 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 10/19] target/ppc: PMU Event-Based exception support Daniel Henrique Barboza
2021-08-10 3:55 ` David Gibson
2021-08-11 0:50 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 11/19] target/ppc/excp_helper.c: POWERPC_EXCP_EBB adjustments Daniel Henrique Barboza
2021-08-09 13:10 ` [PATCH 12/19] target/ppc/pmu_book3s_helper.c: enable PMC1 counter negative EBB Daniel Henrique Barboza
2021-08-10 4:01 ` David Gibson
2021-08-10 20:26 ` Daniel Henrique Barboza
2021-08-11 3:40 ` David Gibson
2021-08-11 11:18 ` Daniel Henrique Barboza
2021-08-12 3:39 ` David Gibson
2021-08-12 4:45 ` Richard Henderson
2021-08-12 4:56 ` Richard Henderson
2021-08-12 10:17 ` Daniel Henrique Barboza
2021-08-12 21:24 ` Daniel Henrique Barboza
2021-08-13 0:35 ` Richard Henderson
2021-08-14 19:13 ` Daniel Henrique Barboza
2021-08-15 19:24 ` Richard Henderson
2021-08-09 13:10 ` [PATCH 13/19] target/ppc/translate: PMU: handle setting of PMCs while running Daniel Henrique Barboza
2021-08-10 4:06 ` David Gibson
2021-08-10 20:44 ` Daniel Henrique Barboza
2021-08-11 3:46 ` David Gibson
2021-08-09 13:10 ` [PATCH 14/19] target/ppc/pmu_book3s_helper.c: add generic timeout helpers Daniel Henrique Barboza
2021-08-10 4:09 ` David Gibson
2021-08-09 13:10 ` [PATCH 15/19] target/ppc/pmu_book3s_helper: enable counter negative for all PMCs Daniel Henrique Barboza
2021-08-10 4:11 ` David Gibson
2021-08-10 21:02 ` Daniel Henrique Barboza
2021-08-12 1:44 ` David Gibson
2021-08-09 13:10 ` [PATCH 16/19] target/ppc/pmu_book3s_helper: adding 0xFA event Daniel Henrique Barboza
2021-08-10 4:13 ` David Gibson
2021-08-09 13:10 ` [PATCH 17/19] target/ppc/pmu_book3s_helper.c: add PMC14/PMC56 counter freeze bits Daniel Henrique Barboza
2021-08-09 13:10 ` [PATCH 18/19] target/ppc/pmu_book3s_helper.c: add PM_CMPLU_STALL mock events Daniel Henrique Barboza
2021-08-10 4:17 ` David Gibson
2021-08-10 19:48 ` Daniel Henrique Barboza
2021-08-11 3:37 ` David Gibson [this message]
2021-08-09 13:10 ` [PATCH 19/19] docs/specs: add PPC64 TCG PMU-EBB documentation Daniel Henrique Barboza
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