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From: Len Brown <lenb@kernel.org>
To: Thomas Renninger <trenn@suse.de>
Cc: linux-perf-users@vger.kernel.org, mingo@elte.hu,
	arjan@linux.intel.com, j-pihet@ti.com,
	linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/9] acpi: processor->cpuidle: Only set cpuidle check_bm flag if pr->flags.bm_check is set
Date: Wed, 12 Jan 2011 02:17:18 -0500 (EST)	[thread overview]
Message-ID: <alpine.LFD.2.02.1101120159400.19140@x980> (raw)
In-Reply-To: <1294396190-23031-6-git-send-email-trenn@suse.de>

On Fri, 7 Jan 2011, Thomas Renninger wrote:

>  drivers/acpi/processor_idle.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index b28693e..82f74c9 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1039,7 +1039,8 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
>  			snprintf(state->abbr, CPUIDLE_ABBR_LEN, "C3");
>  			state->flags |= CPUIDLE_FLAG_DEEP;
>  			state->flags |= CPUIDLE_FLAG_TIME_VALID;
> -			state->flags |= CPUIDLE_FLAG_CHECK_BM;
> +			if (pr->flags.bm_check)
> +				state->flags |= CPUIDLE_FLAG_CHECK_BM;
>  			state->enter = pr->flags.bm_check ?
>  					acpi_idle_enter_bm :
>  					acpi_idle_enter_simple;
> -- 

While it is logical, this patch is a NO-OP, since nobody
ever checks for state->flags |= CPUIDLE_FLAG_CHECK_BM --
not cpuidle, and not the platform driver.

ie. it would be better to delete use of this flag from this file.

This points out a problem w/ cpuidle, of course.
Who owns and defines state->flags -- cpuidle and its governors,
or the cpuidle drivers?

cpuidle and its governors look only at...
CPUIDLE_FLAG_TIME_VALID and CPUIDLE_FLAG_IGNORE

cpuidle sets, but never looks at, CPUIDLE_FLAG_POLL

only intel_idle uses CPUIDLE_FLAG_TLB_FLUSHED,
so it should probably define it.

only OMAP uses CPUIDLE_FLAG_CHECK_BM,
so it should define it (or create a flag
that actually says what they mean here)

CPUIDLE_FLAG_SHALLOW, CPUIDLE_FLAG_BALANCED, CPUIDLE_FLAG_DEEP
are set in various architectures, but never checked,
so they should be deleted.

thanks,
Len Brown, Intel Open Source Technology Center

  reply	other threads:[~2011-01-12  7:17 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-07 10:29 [PATCH 0/9] Make cpu_idle events architecture independent Thomas Renninger
2011-01-07 10:29 ` [PATCH 1/9] acpi: Use ACPI C-state type instead of enumeration value to export cpuidle state name Thomas Renninger
2011-01-07 20:45   ` Len Brown
2011-01-09 12:30     ` Thomas Renninger
2011-01-12  6:36       ` Len Brown
2011-01-12 12:33         ` Thomas Renninger
2011-01-12 22:41           ` Len Brown
2011-01-07 10:29 ` [PATCH 2/9] cpuidle: Rename X86 specific idle poll state[0] from C0 to POLL Thomas Renninger
2011-01-12  6:37   ` Len Brown
2011-01-07 10:29 ` [PATCH 3/9] X86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layer Thomas Renninger
2011-01-12  6:42   ` Len Brown
2011-01-12 15:16     ` Thomas Renninger
2011-01-12 23:12       ` Len Brown
2011-01-07 10:29 ` [PATCH 4/9] cpuidle: Introduce .abbr (abbrevation) for cpuidle states Thomas Renninger
2011-01-07 21:23   ` Kevin Hilman
2011-01-12  6:56   ` Len Brown
2011-01-12 13:37     ` Thomas Renninger
2011-01-12 22:25       ` Len Brown
2011-01-12 23:39         ` Thomas Renninger
2011-01-13 15:42         ` Valdis.Kletnieks
2011-01-07 10:29 ` [PATCH 5/9] acpi: processor->cpuidle: Only set cpuidle check_bm flag if pr->flags.bm_check is set Thomas Renninger
2011-01-12  7:17   ` Len Brown [this message]
2011-01-12  7:30     ` [PATCH] ACPI: processor_idle: delete use of NOP CPUIDLE_FLAGs Len Brown
2011-01-12  7:37       ` [PATCH] cpuidle: delete NOP CPUIDLE_FLAG_POLL Len Brown
2011-01-12  8:00         ` [PATCH] SH, cpuidle: delete use of NOP CPUIDLE_FLAGS_SHALLOW Len Brown
2011-01-12  8:01           ` [PATCH] cpuidle: delete unused CPUIDLE_FLAG_SHALLOW, BALANCED, DEEP definitions Len Brown
2011-01-12  8:02           ` [PATCH] cpuidle: CPUIDLE_FLAG_TLB_FLUSHED is specific to intel_idle Len Brown
2011-01-12  8:04             ` [PATCH] cpuidle: CPUIDLE_FLAG_CHECK_BM is omap3_idle specific Len Brown
2011-01-07 10:29 ` [PATCH 6/9] perf (userspace): Fix variable clash with glibc time() func Thomas Renninger
2011-01-07 10:29 ` [PATCH 7/9] perf (userspace): Introduce --verbose param for perf timechart Thomas Renninger
2011-01-07 10:29 ` [PATCH 8/9] perf timechart: Map power:cpu_idle events to the corresponding cpuidle state Thomas Renninger
2011-01-07 10:52   ` Thomas Renninger
2011-01-07 10:29 ` [PATCH 9/9] perf: timechart: Fix memleak Thomas Renninger

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