kernel.git/arch/x86/kernel/tsc.c, branch linux-2.6.30.y

x86: move rdtsc_barrier() into the TSC vread method

2009-07-02T23:49:56Z

commit 7d96fd41cadc55f4e00231c8c71b8e25c779f122 upstream. The *fence instructions were moved to vsyscall_64.c by commit cb9e35dce94a1b9c59d46224e8a94377d673e204. But this breaks the vDSO, because vread methods are also called from there. Besides, the synchronization might be unnecessary for other time sources than TSC. [ Impact: fix potential time warp in VDSO ] Signed-off-by: Petr Tesarik LKML-Reference: <9d0ea9ea0f866bdc1f4d76831221ae117f11ea67.1243241859.git.ptesarik@suse.cz> Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

clocksource: pass clocksource to read() callback

2009-04-21T20:41:47Z

Pass clocksource pointer to the read() callback for clocksources. This allows us to share the callback between multiple instances. [hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods] [akpm@linux-foundation.org: cleanup] Signed-off-by: Magnus Damm Acked-by: John Stultz Cc: Thomas Gleixner Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2

2009-03-27T16:28:43Z

Conflicts: arch/parisc/kernel/irq.c arch/x86/include/asm/fixmap_64.h arch/x86/include/asm/setup.h kernel/irq/handle.c Semantic merge: arch/x86/include/asm/fixmap.h Signed-off-by: Ingo Molnar

Merge branch 'sched-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-03-26T23:05:01Z

* 'sched-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits) sched: Add comments to find_busiest_group() function sched: Refactor the power savings balance code sched: Optimize the !power_savings_balance during fbg() sched: Create a helper function to calculate imbalance sched: Create helper to calculate small_imbalance in fbg() sched: Create a helper function to calculate sched_domain stats for fbg() sched: Define structure to store the sched_domain statistics for fbg() sched: Create a helper function to calculate sched_group stats for fbg() sched: Define structure to store the sched_group statistics for fbg() sched: Fix indentations in find_busiest_group() using gotos sched: Simple helper functions for find_busiest_group() sched: remove unused fields from struct rq sched: jiffies not printed per CPU sched: small optimisation of can_migrate_task() sched: fix typos in documentation sched: add avg_overlap decay x86, sched_clock(): mark variables read-mostly sched: optimize ttwu vs group scheduling sched: TIF_NEED_RESCHED -> need_reshed() cleanup sched: don't rebalance if attached on NULL domain ...

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq

2009-03-26T18:04:08Z

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: (35 commits) [CPUFREQ] Prevent p4-clockmod from auto-binding to the ondemand governor. [CPUFREQ] Make cpufreq-nforce2 less obnoxious [CPUFREQ] p4-clockmod reports wrong frequency. [CPUFREQ] powernow-k8: Use a common exit path. [CPUFREQ] Change link order of x86 cpufreq modules [CPUFREQ] conservative: remove 10x from def_sampling_rate [CPUFREQ] conservative: fixup governor to function more like ondemand logic [CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not locked [CPUFREQ] conservative: amend author's email address [CPUFREQ] Use swap() in longhaul.c [CPUFREQ] checkpatch cleanups for acpi-cpufreq [CPUFREQ] powernow-k8: Only print error message once, not per core. [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictions [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max} [CPUFREQ] powernow-k8: Always compile powernow-k8 driver with ACPI support [CPUFREQ] Introduce /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_transition_latency [CPUFREQ] checkpatch cleanups for powernow-k8 [CPUFREQ] checkpatch cleanups for ondemand governor. [CPUFREQ] checkpatch cleanups for powernow-k7 [CPUFREQ] checkpatch cleanups for speedstep related drivers. ...

Merge branches 'sched/cleanups' and 'linus' into sched/core

2009-03-18T08:57:02Z

Fast TSC calibration: calculate proper frequency error bounds

2009-03-17T15:13:17Z

In order for ntpd to correctly synchronize the clocks, the frequency of the system clock must not be off by more than 500 ppm (or, put another way, 1:2000), or ntpd will end up giving up on trying to synchronize properly, and ends up reseting the clock in jumps instead. The fast TSC PIT calibration sometimes failed this test - it was assuming that the PIT reads always took about one microsecond each (2us for the two reads to get a 16-bit timer), and that calibrating TSC to the PIT over 15ms should thus be sufficient to get much closer than 500ppm (max 2us error on both sides giving 4us over 15ms: a 270 ppm error value). However, that assumption does not always hold: apparently some hardware is either very much slower at reading the PIT registers, or there was other noise causing at least one machine to get 700+ ppm errors. So instead of using a fixed 15ms timing loop, this changes the fast PIT calibration to read the TSC delta over the individual PIT timer reads, and use the result to calculate the error bars on the PIT read timing properly. We then successfully calibrate the TSC only if the maximum error bars fall below 500ppm. In the process, we also relax the timing to allow up to 25ms for the calibration, although it can happen much faster depending on hardware. Reported-and-tested-by: Jesper Krogh Cc: john stultz Cc: Thomas Gleixner Acked-by: Ingo Molnar Signed-off-by: Linus Torvalds

Fix potential fast PIT TSC calibration startup glitch

2009-03-17T14:58:26Z

During bootup, when we reprogram the PIT (programmable interval timer) to start counting down from 0xffff in order to use it for the fast TSC calibration, we should also make sure to delay a bit afterwards to allow the PIT hardware to actually start counting with the new value. That will happens at the next CLK pulse (1.193182 MHz), so the easiest way to do that is to just wait at least one microsecond after programming the new PIT counter value. We do that by just reading the counter value back once - which will take about 2us on PC hardware. Reported-and-tested-by: john stultz Signed-off-by: Linus Torvalds

x86, sched_clock(): mark variables read-mostly

2009-03-10T18:02:30Z

Impact: micro-optimization There's a number of variables in the sched_clock() path that are in .data/.bss - but not marked __read_mostly. This creates the danger of accidental false cacheline sharing with some other, write-often variable. So mark them __read_mostly. Signed-off-by: Ingo Molnar

[CPUFREQ] p4-clockmod reports wrong frequency.

2009-02-25T03:47:32Z

http://bugzilla.kernel.org/show_bug.cgi?id=10968 [ Updated for current tree, and fixed compile failure when p4-clockmod was built modular -- davej] From: Matthias-Christian Ott Signed-off-by: Dominik Brodowski Signed-off-by: Dave Jones