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* x86/tsc: Reduce the TSC sync check time for core-siblingsSuresh Siddha2012-02-221-5/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For each logical CPU that is coming online, we spend 20msec for checking the TSC synchronization. And as this is done sequentially for each logical CPU boot, this time gets added up depending on the number of logical CPU's supported by the platform. Minimize this by using the socket topology information. If the target CPU coming online doesn't have any of its core-siblings online, a timeout of 20msec will be used for the TSC-warp measurement loop. Otherwise a smaller timeout of 2msec will be used, as we have some information about this socket already (and this information grows as we have more and more logical-siblings in that socket). Ideally we should be able to skip the TSC sync check on the other core-siblings, if the first logical CPU in a socket passed the sync test. But as the TSC is per-logical CPU and can potentially be modified wrongly by the bios before the OS boot, TSC sync test for smaller duration should be able to catch such errors. Also this will catch the condition where all the cores in the socket doesn't get reset at the same time. For example, with this modification, time spent in TSC sync checks on a 4 socket 10-core with HT system gets reduced from 1580msec to 212msec. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jack Steiner <steiner@sgi.com> Cc: venki@google.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1328581940.29790.20.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, tsc: Skip TSC synchronization checks for tsc=reliableSuresh Siddha2011-12-051-2/+2
| | | | | | | | | | | | | | | | | | | | tsc=reliable boot parameter is supposed to skip all the TSC stablility checks during boot time. On a 8-socket system where we want to run an experiment with the "tsc=reliable" boot option, TSC synchronization checks are not getting skipped and marking the TSC as not stable. Check for tsc_clocksource_reliable (which is set via tsc=reliable or for platforms supporting synthetic TSC_RELIABLE feature bit etc) and when set, skip the TSC synchronization tests during boot. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: John Stultz <johnstul@us.ibm.com> Tested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1320446537.15071.14.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner2009-12-141-4/+4
| | | | | | | | | | Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKEDThomas Gleixner2009-12-141-1/+1
| | | | | | | | | | Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Convert raw_spinlock to arch_spinlockThomas Gleixner2009-12-141-1/+1
| | | | | | | | | | | | | | | | | | | The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* x86: Limit number of per cpu TSC sync messagesMike Travis2009-11-261-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Limit the number of per cpu TSC sync messages by only printing to the console if an error occurs, otherwise print as a DEBUG message. The info message "Skipping synchronization ..." is only printed after the last cpu has booted. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091118002222.181053000@alcatraz.americas.sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: Reduce verbosity of "TSC is reliable" messageRoland Dreier2009-09-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | On modern systems, the kernel prints the message Skipping synchronization checks as TSC is reliable. once for every non-boot CPU. This gets kind of ridiculous on huge systems; for example, on a 64-thread system I was lucky enough to get: $ dmesg | grep 'TSC is reliable' | wc 63 567 4221 There's no point to doing this for every CPU, since the code is just checking the boot CPU anyway, so change this to a printk_once() to make the message appears only once. Signed-off-by: Roland Dreier <rolandd@cisco.com> LKML-Reference: <adazl8l2swc.fsf@cisco.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: clean up arch/x86/kernel/tsc_sync.c a bitIngo Molnar2009-05-071-8/+6
| | | | | | | | | | | - remove unused define - make the lock variable definition stand out some more - convert KERN_* to pr_info() / pr_warning() [ Impact: cleanup ] LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
*-. Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', ↵Ingo Molnar2008-12-231-1/+7
|\ \ | | | | | | | | | 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core
| | * x86: Add a synthetic TSC_RELIABLE feature bit.Alok Kataria2008-11-011-1/+7
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Changes timebase calibration on Vmware. Use the synthetic TSC_RELIABLE bit to workaround virtualization anomalies. Virtual TSCs can be kept nearly in sync, but because the virtual TSC offset is set by software, it's not perfect. So, the TSC synchronization test can fail. Even then the TSC can be used as a clocksource since the VMware platform exports a reliable TSC to the guest for timekeeping purposes. Use this bit to check if we need to skip the TSC sync checks. Along with this also set the CONSTANT_TSC bit when on VMware, since we still want to use TSC as clocksource on VM running over hardware which has unsynchronized TSC's (opteron's), since the hypervisor will take care of providing consistent TSC to the guest. Signed-off-by: Alok N Kataria <akataria@vmware.com> Signed-off-by: Dan Hecht <dhecht@vmware.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86: add rdtsc barrier to TSC sync checkVenki Pallipadi2008-11-181-0/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix incorrectly marked unstable TSC clock Patch (commit 0d12cdd "sched: improve sched_clock() performance") has a regression on one of the test systems here. With the patch, I see: checking TSC synchronization [CPU#0 -> CPU#1]: Measured 28 cycles TSC warp between CPUs, turning off TSC clock. Marking TSC unstable due to check_tsc_sync_source failed Whereas, without the patch syncs pass fine on all CPUs: checking TSC synchronization [CPU#0 -> CPU#1]: passed. Due to this, TSC is marked unstable, when it is not actually unstable. This is because syncs in check_tsc_wrap() goes away due to this commit. As per the discussion on this thread, correct way to fix this is to add explicit syncs as below? Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: use WARN() in arch/x86/kernelArjan van de Ven2008-08-211-4/+2
| | | | | | | | | | Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. This also allowed the folding of some if()'s into the WARN() Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: akpm@linux-foundation.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: add warning to check_tsc_warp()Ingo Molnar2008-01-301-1/+5
| | | | | | | add warning to check_tsc_warp() - if get_cycles() does not progress. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: check_tsc_warp() slowness fixIngo Molnar2008-01-301-2/+2
| | | | | | | 100 million max # of loops is a bit too much - reduce it to 10 million. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: remove get_cycles_syncAndi Kleen2008-01-301-2/+2
| | | | | | | | | | | rdtsc is now speculation-safe, so no need for the sync variants of the APIs. [ mingo@elte.hu: removed the nsec_barrier() complication. ] Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: fix: s2ram + P4 + tsc = annoyanceMike Galbraith2008-01-301-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s2ram recently became useful here, except for the kernel's annoying habit of disabling my P4's perfectly good TSC. [ 107.894470] CPU 1 is now offline [ 107.894474] SMP alternatives: switching to UP code [ 107.895832] CPU0 attaching sched-domain: [ 107.895836] domain 0: span 1 [ 107.895838] groups: 1 [ 107.896097] CPU1 is down [ 3.726156] Intel machine check architecture supported. [ 3.726165] Intel machine check reporting enabled on CPU#0. [ 3.726167] CPU0: Intel P4/Xeon Extended MCE MSRs (12) available [ 3.726170] CPU0: Thermal monitoring enabled [ 3.726175] Back to C! [ 3.726708] Force enabled HPET at resume [ 3.726775] Enabling non-boot CPUs ... [ 3.727049] CPU0 attaching NULL sched-domain. [ 3.727165] SMP alternatives: switching to SMP code [ 3.727858] Booting processor 1/1 eip 3000 [ 3.727862] CPU 1 irqstacks, hard=b042f000 soft=b042d000 [ 3.738173] Initializing CPU#1 [ 3.798912] Calibrating delay using timer specific routine.. 5986.12 BogoMIPS (lpj=2993061) [ 3.798920] CPU: After generic identify, caps: bfebfbff 00000000 00000000 00000000 00004400 00000000 00000000 00000000 [ 3.798931] CPU: Trace cache: 12K uops, L1 D cache: 8K [ 3.798934] CPU: L2 cache: 512K [ 3.798936] CPU: Physical Processor ID: 0 [ 3.798938] CPU: After all inits, caps: bfebfbff 00000000 00000000 0000b080 00004400 00000000 00000000 00000000 [ 3.798946] Intel machine check architecture supported. [ 3.798952] Intel machine check reporting enabled on CPU#1. [ 3.798955] CPU1: Intel P4/Xeon Extended MCE MSRs (12) available [ 3.798959] CPU1: Thermal monitoring enabled [ 3.799161] CPU1: Intel(R) Pentium(R) 4 CPU 3.00GHz stepping 09 [ 3.799187] checking TSC synchronization [CPU#0 -> CPU#1]: [ 3.819181] Measured 63588552840 cycles TSC warp between CPUs, turning off TSC clock. [ 3.819184] Marking TSC unstable due to: check_tsc_sync_source failed. If check_tsc_warp() is called after initial boot, and the TSC has in the meantime been set (BIOS, user, silicon, elves) to a value lower than the last stored/stale value, we blame the TSC. Reset to pristine condition after every test. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Delete filenames in comments.Dave Jones2007-10-131-1/+1
| | | | | | | | | | | | | | | 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: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86_64: move kernelThomas Gleixner2007-10-111-1/+187
| | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* i386: move kernelThomas Gleixner2007-10-111-0/+1
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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