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2008-05-17x86: disable mwait for AMD family 10H/11H CPUsThomas Gleixner
The previous revert of 0c07ee38c9d4eb081758f5ad14bbffa7197e1aec left out the mwait disable condition for AMD family 10H/11H CPUs. Andreas Herrman said: It depends on the CPU. For AMD CPUs that support MWAIT this is wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings then depend on a clock divisor and current Pstate of the core. If all cores of a processor are in halt state (C1) the processor can enter the C1E (C1 enhanced) state. If mwait is used this will never happen. Thus HLT saves more power than MWAIT here. It might be best to switch off the mwait flag for these AMD CPU families like it was introduced with commit f039b754714a422959027cb18bb33760eb8153f0 (x86: Don't use MWAIT on AMD Family 10) Re-add the AMD families 10H/11H check and disable the mwait usage for those. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-17x86: remove mwait capability C-state checkIngo Molnar
Vegard Nossum reports: | powertop shows between 200-400 wakeups/second with the description | "<kernel IPI>: Rescheduling interrupts" when all processors have load (e.g. | I need to run two busy-loops on my 2-CPU system for this to show up). | | The bisect resulted in this commit: | | commit 0c07ee38c9d4eb081758f5ad14bbffa7197e1aec | Date: Wed Jan 30 13:33:16 2008 +0100 | | x86: use the correct cpuid method to detect MWAIT support for C states remove the functional effects of this patch and make mwait unconditional. A future patch will turn off mwait on specific CPUs where that causes power to be wasted. Bisected-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-27fix idle (arch, acpi and apm) and lockdepPeter Zijlstra
OK, so 25-mm1 gave a lockdep error which made me look into this. The first thing that I noticed was the horrible mess; the second thing I saw was hacks like: 71e93d15612c61c2e26a169567becf088e71b8ff The problem is that arch idle routines are somewhat inconsitent with their IRQ state handling and instead of fixing _that_, we go paper over the problem. So the thing I've tried to do is set a standard for idle routines and fix them all up to adhere to that. So the rules are: idle routines are entered with IRQs disabled idle routines will exit with IRQs enabled Nearly all already did this in one form or another. Merge the 32 and 64 bit bits so they no longer have different bugs. As for the actual lockdep warning; __sti_mwait() did a plainly un-annotated irq-enable. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19x86: fpu xstate split cleanupSuresh Siddha
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19x86, fpu: lazy allocation of FPU area - v5Suresh Siddha
Only allocate the FPU area when the application actually uses FPU, i.e., in the first lazy FPU trap. This could save memory for non-fpu using apps. for example: on my system after boot, there are around 300 processes, with only 17 using FPU. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19x86, fpu: split FPU state from task struct - v5Suresh Siddha
Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>