The patch titled
i386 tsc: remove xtime_lock'ing around cpufreq notifier
has been added to the -mm tree. Its filename is
i386-tsc-remove-xtime_locking-around-cpufreq-notifier.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: i386 tsc: remove xtime_lock'ing around cpufreq notifier
From: Daniel Walker <dwalker@xxxxxxxxxx>
The locking of the xtime_lock around the cpu notifier is unessesary now.
At one time the tsc was used after a frequency change for timekeeping, but
the re-write of timekeeping no longer uses the TSC unless the frequency is
constant.
The variables that are changed in this section of code had also once been
used for timekeeping, but not any longer ..
Signed-off-by: Daniel Walker <dwalker@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/i386/kernel/tsc.c | 8 +-------
1 files changed, 1 insertion(+), 7 deletions(-)
diff -puN arch/i386/kernel/tsc.c~i386-tsc-remove-xtime_locking-around-cpufreq-notifier arch/i386/kernel/tsc.c
--- a/arch/i386/kernel/tsc.c~i386-tsc-remove-xtime_locking-around-cpufreq-notifier
+++ a/arch/i386/kernel/tsc.c
@@ -200,13 +200,10 @@ time_cpufreq_notifier(struct notifier_bl
{
struct cpufreq_freqs *freq = data;
- if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
- write_seqlock_irq(&xtime_lock);
-
if (!ref_freq) {
if (!freq->old){
ref_freq = freq->new;
- goto end;
+ return 0;
}
ref_freq = freq->old;
loops_per_jiffy_ref = cpu_data[freq->cpu].loops_per_jiffy;
@@ -237,9 +234,6 @@ time_cpufreq_notifier(struct notifier_bl
}
}
}
-end:
- if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
- write_sequnlock_irq(&xtime_lock);
return 0;
}
_
Patches currently in -mm which might be from dwalker@xxxxxxxxxx are
i386-tsc-remove-xtime_locking-around-cpufreq-notifier.patch
clocksource-acpi_pm-trivial-comment-update.patch
slim-make-and-config-stuff.patch
profile-likely-unlikely-macros.patch
-
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