- 30 1月, 2008 1 次提交
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由 Ingo Molnar 提交于
do a proper idle-wakeup event on HLT as well - some CPUs stop the TSC in HLT too, not just when going through the ACPI methods. (the ACPI idle code already does this.) [ update the 64-bit side too, as noticed by Jiri Slaby. ] Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 15 1月, 2008 1 次提交
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由 Steven Rostedt 提交于
Sometimes cpu_idle_wait gets stuck because it might miss CPUS that are already in idle, have no tasks waiting to run and have no interrupts going to them. This is common on bootup when switching cpu idle governors. This patch gives those CPUS that don't check in an IPI kick. Background: ----------- I notice this while developing the mcount patches, that every once in a while the system would hang. Looking deeper, the hang was always at boot up when registering init_menu of the cpu_idle menu governor. Talking with Thomas Gliexner, we discovered that one of the CPUS had no timer events scheduled for it and it was in idle (running with NO_HZ). So the CPU would not set the cpu_idle_state bit. Hitting sysrq-t a few times would eventually route the interrupt to the stuck CPU and the system would continue. Note, I would have used the PDA isidle but that is set after the cpu_idle_state bit is cleared, and would leave a window open where we may miss being kicked. hmm, looking closer at this, we still have a small race window between clearing the cpu_idle_state and disabling interrupts (hence the RFC). CPU0: CPU 1: --------- --------- cpu_idle_wait(): cpu_idle(): | __cpu_cpu_var(is_idle) = 1; | if (__get_cpu_var(cpu_idle_state)) /* == 0 */ per_cpu(cpu_idle_state, 1) = 1; | if (per_cpu(is_idle, 1)) /* == 1 */ | smp_call_function(1) | | receives ipi and runs do_nothing. wait on map == empty idle(); /* waits forever */ So really we need interrupts off for most of this then. One might think that we could simply clear the cpu_idle_state from do_nothing, but I'm assuming that cpu_idle governors can be removed, and this might cause a race that a governor might be used after the module was removed. Venki said: I think your RFC patch is the right solution here. As I see it, there is no race with your RFC patch. As long as you call a dummy smp_call_function on all CPUs, we should be OK. We can get rid of cpu_idle_state and the current wait forever logic altogether with dummy smp_call_function. And so there wont be any wait forever scenario. The whole point of cpu_idle_wait() is to make all CPUs come out of idle loop atleast once. The caller will use cpu_idle_wait something like this. // Want to change idle handler - Switch global idle handler to always present default_idle - call cpu_idle_wait so that all cpus come out of idle for an instant and stop using old idle pointer and start using default idle - Change the idle handler to a new handler - optional cpu_idle_wait if you want all cpus to start using the new handler immediately. Maybe the below 1s patch is safe bet for .24. But for .25, I would say we just replace all complicated logic by simple dummy smp_call_function and remove cpu_idle_state altogether. Signed-off-by: NSteven Rostedt <srostedt@redhat.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: NIngo Molnar <mingo@elte.hu> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Cc: Len Brown <lenb@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 12月, 2007 1 次提交
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由 Adrian Bunk 提交于
CONFIG_HOTPLUG_CPU=y: WARNING: vmlinux.o(.text+0x1199a): Section mismatch: reference to .init.text.5:select_idle_routine (between 'init_intel' and 'init_nexgen') Signed-off-by: NAdrian Bunk <bunk@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 20 10月, 2007 2 次提交
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由 Alexey Dobriyan 提交于
One of the easiest things to isolate is the pid printed in kernel log. There was a patch, that made this for arch-independent code, this one makes so for arch/xxx files. It took some time to cross-compile it, but hopefully these are all the printks in arch code. Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org> Signed-off-by: NPavel Emelyanov <xemul@openvz.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Pavel Emelyanov 提交于
Both functions printk the same information, except for CRx and debug registers in the show_registers() one and a bit different manner. So move the common code into one place. This is already done for x86_64, so I think it's worth having the same on i386. This saves 100 bytes of .rodata section :) ... but only 8 from .text :( [ tglx: arch/x86 adaptation ] Signed-off-by: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NAndi Kleen <ak@suse.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 14 10月, 2007 1 次提交
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由 Dave Jones 提交于
Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: NDave Jones <davej@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 10月, 2007 2 次提交
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 22 7月, 2007 1 次提交
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由 Alan Stern 提交于
This patch (as921) adds code to the show_regs() routine in i386 and x86_64 to print the contents of the debug registers along with all the others. Signed-off-by: NAlan Stern <stern@rowland.harvard.edu> Signed-off-by: NRoland McGrath <roland@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NAndi Kleen <ak@suse.de> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 7月, 2007 1 次提交
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由 Andrea Arcangeli 提交于
This follows a suggestion from Chuck Ebbert on how to make seccomp absolutely zerocost in schedule too. The only remaining footprint of seccomp is in terms of the bzImage size that becomes a few bytes (perhaps even a few kbytes) larger, measure it if you care in the embedded. Signed-off-by: NAndrea Arcangeli <andrea@cpushare.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 5月, 2007 1 次提交
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由 Christoph Lameter 提交于
SLUB cannot run on i386 at this point because i386 uses the page->private and page->index field of slab pages for the pgd cache. Make SLUB run on i386 by replacing the pgd slab cache with a quicklist. Limit the changes as much as possible. Leave the improvised linked list in place etc etc. This has been working here for a couple of weeks now. Acked-by: NWilliam Lee Irwin III <wli@holomorphy.com> Signed-off-by: NChristoph Lameter <clameter@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 5月, 2007 1 次提交
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由 Randy Dunlap 提交于
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 5月, 2007 3 次提交
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由 Jeremy Fitzhardinge 提交于
Currently x86 (similar to x84-64) has a special per-cpu structure called "i386_pda" which can be easily and efficiently referenced via the %fs register. An ELF section is more flexible than a structure, allowing any piece of code to use this area. Indeed, such a section already exists: the per-cpu area. So this patch: (1) Removes the PDA and uses per-cpu variables for each current member. (2) Replaces the __KERNEL_PDA segment with __KERNEL_PERCPU. (3) Creates a per-cpu mirror of __per_cpu_offset called this_cpu_off, which can be used to calculate addresses for this CPU's variables. (4) Simplifies startup, because %fs doesn't need to be loaded with a special segment at early boot; it can be deferred until the first percpu area is allocated (or never for UP). The result is less code and one less x86-specific concept. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de>
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由 Rusty Russell 提交于
On Thu, 2007-03-29 at 13:16 +0200, Andi Kleen wrote: > Please clean it up properly with two structs. Not sure about this, now I've done it. Running it here. If you like it, I can do x86-64 as well. == lguest defines its own TSS struct because the "struct tss_struct" contains linux-specific additions. Andi asked me to split the struct in processor.h. Unfortunately it makes usage a little awkward. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Andi Kleen 提交于
It doesn't put the CPU into deeper sleep states, so it's better to use the standard idle loop to save power. But allow to reenable it anyways for benchmarking. I also removed the obsolete idle=halt on i386 Cc: andreas.herrmann@amd.com Signed-off-by: NAndi Kleen <ak@suse.de>
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- 27 2月, 2007 1 次提交
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由 Linus Torvalds 提交于
This reverts commit 2ff2d3d7. Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri Slaby bisected it down to this commit. Benjamin LaHaise also points out that this is a big hot-path, and that interrupt delivery while idle is very common and should not go through all these expensive gyrations. Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c due to other unrelated irq changes. Cc: Stephane Eranian <eranian@hpl.hp.com> Cc: Andi Kleen <ak@suse.de> Cc: Andrew Morton <akpm@osdl.org> Cc: Uwe Bugla <uwe.bugla@gmx.de> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 2月, 2007 1 次提交
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由 Ingo Molnar 提交于
Prepare i386 for dyntick: idle handler callbacks. Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 2月, 2007 4 次提交
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由 Stephane Eranian 提交于
Add a notifier mechanism to the low level idle loop. You can register a callback function which gets invoked on entry and exit from the low level idle loop. The low level idle loop is defined as the polling loop, low-power call, or the mwait instruction. Interrupts processed by the idle thread are not considered part of the low level loop. The notifier can be used to measure precisely how much is spent in useless execution (or low power mode). The perfmon subsystem uses it to turn on/off monitoring. Signed-off-by: Nstephane eranian <eranian@hpl.hp.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Zachary Amsden 提交于
I found a clever way to make the extra IOPL switching invisible to non-paravirt compiles - since kernel_rpl is statically defined to be zero there, and only non-zero rpl kernel have a problem restoring IOPL, as popf does not restore IOPL flags unless run at CPL-0. Signed-off-by: NZachary Amsden <zach@vmware.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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由 Zachary Amsden 提交于
The VMI ROM has a mode where hypercalls can be queued and batched. This turns out to be a significant win during context switch, but must be done at a specific point before side effects to CPU state are visible to subsequent instructions. This is similar to the MMU batching hooks already provided. The same hooks could be used by the Xen backend to implement a context switch multicall. To explain a bit more about lazy modes in the paravirt patches, basically, the idea is that only one of lazy CPU or MMU mode can be active at any given time. Lazy MMU mode is similar to this lazy CPU mode, and allows for batching of multiple PTE updates (say, inside a remap loop), but to avoid keeping some kind of state machine about when to flush cpu or mmu updates, we just allow one or the other to be active. Although there is no real reason a more comprehensive scheme could not be implemented, there is also no demonstrated need for this extra complexity. Signed-off-by: NZachary Amsden <zach@vmware.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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由 Jeremy Fitzhardinge 提交于
Convert the PDA code to use %fs rather than %gs as the segment for per-processor data. This is because some processors show a small but measurable performance gain for reloading a NULL segment selector (as %fs generally is in user-space) versus a non-NULL one (as %gs generally is). On modern processors the difference is very small, perhaps undetectable. Some old AMD "K6 3D+" processors are noticably slower when %fs is used rather than %gs; I have no idea why this might be, but I think they're sufficiently rare that it doesn't matter much. This patch also fixes the math emulator, which had not been adjusted to match the changed struct pt_regs. [frederik.deweerdt@gmail.com: fixit with gdb] [mingo@elte.hu: Fix KVM too] Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Ian Campbell <Ian.Campbell@XenSource.com> Acked-by: NIngo Molnar <mingo@elte.hu> Acked-by: NZachary Amsden <zach@vmware.com> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: NFrederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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- 23 12月, 2006 1 次提交
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由 Ingo Molnar 提交于
Fernando Lopez-Lezcano reported frequent scheduling latencies and audio xruns starting at the 2.6.18-rt kernel, and those problems persisted all until current -rt kernels. The latencies were serious and unjustified by system load, often in the milliseconds range. After a patient and heroic multi-month effort of Fernando, where he tested dozens of kernels, tried various configs, boot options, test-patches of mine and provided latency traces of those incidents, the following 'smoking gun' trace was captured by him: _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup (try_to_wake_up) IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup <<...>-5856> (37 0) IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup (c01262ba 0 0) IRQ_19-1479 1D..1 0us : resched_task (try_to_wake_up) IRQ_19-1479 1D..1 0us : __spin_unlock_irqrestore (try_to_wake_up) ... <idle>-0 1...1 11us!: default_idle (cpu_idle) ... <idle>-0 0Dn.1 602us : smp_apic_timer_interrupt (c0103baf 1 0) ... <...>-5856 0D..2 618us : __switch_to (__schedule) <...>-5856 0D..2 618us : __schedule <<idle>-0> (20 162) <...>-5856 0D..2 619us : __spin_unlock_irq (__schedule) <...>-5856 0...1 619us : trace_stop_sched_switched (__schedule) <...>-5856 0D..1 619us : trace_stop_sched_switched <<...>-5856> (37 0) what is visible in this trace is that CPU#1 ran try_to_wake_up() for PID:5856, it placed PID:5856 on CPU#0's runqueue and ran resched_task() for CPU#0. But it decided to not send an IPI that no CPU - due to TS_POLLING. But CPU#0 never woke up after its NEED_RESCHED bit was set, and only rescheduled to PID:5856 upon the next lapic timer IRQ. The result was a 600+ usecs latency and a missed wakeup! the bug turned out to be an idle-wakeup bug introduced into the mainline kernel this summer via an optimization in the x86_64 tree: commit 495ab9c0 Author: Andi Kleen <ak@suse.de> Date: Mon Jun 26 13:59:11 2006 +0200 [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status During some profiling I noticed that default_idle causes a lot of memory traffic. I think that is caused by the atomic operations to clear/set the polling flag in thread_info. There is actually no reason to make this atomic - only the idle thread does it to itself, other CPUs only read it. So I moved it into ti->status. the problem is this type of change: if (!hlt_counter && boot_cpu_data.hlt_works_ok) { - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); while (!need_resched()) { local_irq_disable(); this changes clear_thread_flag() to an explicit clearing of TS_POLLING. clear_thread_flag() is defined as: clear_bit(flag, &ti->flags); and clear_bit() is a LOCK-ed atomic instruction on all x86 platforms: static inline void clear_bit(int nr, volatile unsigned long * addr) { __asm__ __volatile__( LOCK_PREFIX "btrl %1,%0" hence smp_mb__after_clear_bit() is defined as a simple compile barrier: #define smp_mb__after_clear_bit() barrier() but the explicit TS_POLLING clearing introduced by the patch: + current_thread_info()->status &= ~TS_POLLING; is not an atomic op! So the clearing of the TS_POLLING bit is freely reorderable with the reading of the NEED_RESCHED bit - and both now reside in different memory addresses. CPU idle wakeup very much depends on ordered memory ops, the clearing of the TS_POLLING flag must always be done before we test need_resched() and hit the idle instruction(s). [Symmetrically, the wakeup code needs to set NEED_RESCHED before it tests the TS_POLLING flag, so memory ordering is paramount.] Fernando's dual-core Athlon64 system has a sufficiently advanced memory ordering model so that it triggered this scenario very often. ( And it also turned out that the reason why these latencies never triggered on my testsystems is that i routinely use idle=poll, which was the only idle variant not affected by this bug. ) The fix is to change the smp_mb__after_clear_bit() to an smp_mb(), to act as an absolute barrier between the TS_POLLING write and the NEED_RESCHED read. This affects almost all idling methods (default, ACPI, APM), on all 3 x86 architectures: i386, x86_64, ia64. Signed-off-by: NIngo Molnar <mingo@elte.hu> Tested-by: NFernando Lopez-Lezcano <nando@ccrma.Stanford.EDU> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 07 12月, 2006 6 次提交
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由 Chuck Ebbert 提交于
IOPL is implicitly saved and restored on task switch, so explicit check is no longer needed. Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Andi Kleen 提交于
Currently the idle loop has two nested loops -- one high level in cpu_idle and in some low level idle functions another one. Looping in the low level idle functions breaks the idle notifiers because interrupts waking up sleep states need to execute exit_idle() which is only in cpu_idle(). So don't do that, only loop in cpu_idle(). This only removes code. In some cases e.g. poll_idle the idle loop is a little longer now because cpu_idle checks more things. I hope that isn't a problem ACPI idle doesn't change behaviour because it never looped anyways. Cc: len.brown@intel.com Cc: eranian@hpl.hp.com Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Jeremy Fitzhardinge 提交于
Use the pcurrent field in the PDA to implement the "current" macro. This ends up compiling down to a single instruction to get the current task. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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由 Jeremy Fitzhardinge 提交于
There are a few places where the change in struct pt_regs and the use of %gs affect the userspace ABI. These are primarily debugging interfaces where thread state can be inspected or extracted. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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由 Jeremy Fitzhardinge 提交于
This patch is the meat of the PDA change. This patch makes several related changes: 1: Most significantly, %gs is now used in the kernel. This means that on entry, the old value of %gs is saved away, and it is reloaded with __KERNEL_PDA. 2: entry.S constructs the stack in the shape of struct pt_regs, and this is passed around the kernel so that the process's saved register state can be accessed. Unfortunately struct pt_regs doesn't currently have space for %gs (or %fs). This patch extends pt_regs to add space for gs (no space is allocated for %fs, since it won't be used, and it would just complicate the code in entry.S to work around the space). 3: Because %gs is now saved on the stack like %ds, %es and the integer registers, there are a number of places where it no longer needs to be handled specially; namely context switch, and saving/restoring the register state in a signal context. 4: And since kernel threads run in kernel space and call normal kernel code, they need to be created with their %gs == __KERNEL_PDA. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org>
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由 Chuck Ebbert 提交于
i386 port of the sLeAZY-fpu feature. Chuck reports that this gives him a +/- 0.4% improvement on his simple benchmark x86_64 description follows: Right now the kernel on x86-64 has a 100% lazy fpu behavior: after *every* context switch a trap is taken for the first FPU use to restore the FPU context lazily. This is of course great for applications that have very sporadic or no FPU use (since then you avoid doing the expensive save/restore all the time). However for very frequent FPU users... you take an extra trap every context switch. The patch below adds a simple heuristic to this code: After 5 consecutive context switches of FPU use, the lazy behavior is disabled and the context gets restored every context switch. If the app indeed uses the FPU, the trap is avoided. (the chance of the 6th time slice using FPU after the previous 5 having done so are quite high obviously). After 256 switches, this is reset and lazy behavior is returned (until there are 5 consecutive ones again). The reason for this is to give apps that do longer bursts of FPU use still the lazy behavior back after some time. Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com> Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NAndi Kleen <ak@suse.de>
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- 18 11月, 2006 1 次提交
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由 Ingo Molnar 提交于
The scheduler on Andreas Friedrich's hyperthreading system stopped working properly: the scheduler would never move tasks to another CPU! The lask known working kernel was 2.6.8. After a couple of attempts to corner the bug, the following smoking gun was found: BIOS reported wrong ACPI idfor the processor CPU#1: set_cpus_allowed(), swapper:1, 3 -> 2 [<c0103bbe>] show_trace_log_lvl+0x34/0x4a [<c0103ceb>] show_trace+0x2c/0x2e [<c01045f8>] dump_stack+0x2b/0x2d [<c0116a77>] set_cpus_allowed+0x52/0xec [<c0101d86>] cpu_idle_wait+0x2e/0x100 [<c0259c57>] acpi_processor_power_exit+0x45/0x58 [<c0259752>] acpi_processor_remove+0x46/0xea [<c025c6fb>] acpi_start_single_object+0x47/0x54 [<c025cee5>] acpi_bus_register_driver+0xa4/0xd3 [<c04ab2d7>] acpi_processor_init+0x57/0x77 [<c01004d7>] init+0x146/0x2fd [<c0103a87>] kernel_thread_helper+0x7/0x10 a quick look at cpu_idle_wait() shows how broken that code is on i386: it changes the init task's affinity map but never restores it ... and because all userspace tasks get forked by init, they all inherited that single-CPU affinity mask. x86_64 cloned this bug too. Signed-off-by: NIngo Molnar <mingo@elte.hu> Cc: Andreas Friedrich <andreas.friedrich@fujitsu-siemens.com> Cc: Wolfgang Erig <Wolfgang.Erig@fujitsu-siemens.com> Cc: Andrew Morton <akpm@osdl.org> Cc: Adrian Bunk <bunk@stusta.de> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 22 10月, 2006 1 次提交
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由 Andi Kleen 提交于
Jan convinced me that it was unnecessary because the assembly stubs do this already on the stack. Cc: jbeulich@novell.com Signed-off-by: NAndi Kleen <ak@suse.de>
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- 14 10月, 2006 1 次提交
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由 Venkatesh Pallipadi 提交于
Intel processors starting with the Core Duo support support processor native C-state using the MWAIT instruction. Refer: Intel Architecture Software Developer's Manual http://www.intel.com/design/Pentium4/manuals/253668.htm Platform firmware exports the support for Native C-state to OS using ACPI _PDC and _CST methods. Refer: Intel Processor Vendor-Specific ACPI: Interface Specification http://www.intel.com/technology/iapc/acpi/downloads/302223.htm With Processor Native C-state, we use 'MWAIT' instruction on the processor to enter different C-states (C1, C2, C3). We won't use the special IO ports to enter C-state and no SMM mode etc required to enter C-state. Overall this will mean better C-state support. One major advantage of using MWAIT for all C-states is, with this and "treat interrupt as break event" feature of MWAIT, we can now get accurate timing for the time spent in C1, C2, .. states. Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLen Brown <len.brown@intel.com>
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- 06 10月, 2006 1 次提交
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由 Andi Kleen 提交于
Always make sure RIP/EIP is 0 in the registers stored on the top of the stack of a kernel thread. This makes sure the unwinder code won't try a fallback but knows the stack has ended. AK: this patch is a bit mysterious. in theory they should be terminated anyways, but it seems to fix at least one crash. Anyways double termination probably doesn't hurt. Signed-off-by: NAndi Kleen <ak@suse.de>
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- 02 10月, 2006 1 次提交
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由 Serge E. Hallyn 提交于
In some places, particularly drivers and __init code, the init utsns is the appropriate one to use. This patch replaces those with a the init_utsname helper. Changes: Removed several uses of init_utsname(). Hope I picked all the right ones in net/ipv4/ipconfig.c. These are now changed to utsname() (the per-process namespace utsname) in the previous patch (2/7) [akpm@osdl.org: CIFS fix] Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 01 10月, 2006 1 次提交
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由 Alexey Dobriyan 提交于
Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 26 9月, 2006 3 次提交
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由 Rusty Russell 提交于
We allow for the fact that the guest kernel may not run in ring 0. This requires some abstraction in a few places when setting %cs or checking privilege level (user vs kernel). This is Chris' [RFC PATCH 15/33] move segment checks to subarch, except rather than using #define USER_MODE_MASK which depends on a config option, we use Zach's more flexible approach of assuming ring 3 == userspace. I also used "get_kernel_rpl()" over "get_kernel_cs()" because I think it reads better in the code... 1) Remove the hardcoded 3 and introduce #define SEGMENT_RPL_MASK 3 2) Add a get_kernel_rpl() macro, and don't assume it's zero. And: Clean up of patch for letting kernel run other than ring 0: a. Add some comments about the SEGMENT_IS_*_CODE() macros. b. Add a USER_RPL macro. (Code was comparing a value to a mask in some places and to the magic number 3 in other places.) c. Add macros for table indicator field and use them. d. Change the entry.S tests for LDT stack segment to use the macros Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NZachary Amsden <zach@vmware.com> Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Andi Kleen 提交于
And add proper CFI annotation to it which was previously impossible. This prevents "stuck" messages by the dwarf2 unwinder when reaching the top of a kernel stack. Includes feedback from Jan Beulich Cc: jbeulich@novell.com Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Andi Kleen 提交于
Based on patch from Frank van Maarseveen <frankvm@frankvm.com>, but extended. Signed-off-by: NAndi Kleen <ak@suse.de>
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- 29 7月, 2006 1 次提交
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由 Chuck Ebbert 提交于
Recent changes in i386 __switch_to() have a misplaced closing parenthesis causing an unlikely() to terminate early. Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 10 7月, 2006 1 次提交
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由 Stephane Eranian 提交于
Use thread info flags to track use of debug registers and IO bitmaps. - add TIF_DEBUG to track when debug registers are active - add TIF_IO_BITMAP to track when I/O bitmap is used - modify __switch_to() to use the new TIF flags Performance tested on Pentium II, ten runs of LMbench context switch benchmark (smaller is better:) before after avg 3.65 3.39 min 3.55 3.33 Signed-off-by: NStephane Eranian <eranian@hpl.hp.com> Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com> Acked-by: NAndi Kleen <ak@suse.de> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 01 7月, 2006 1 次提交
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由 Jörn Engel 提交于
Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: NAdrian Bunk <bunk@stusta.de>
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