- 30 Jan, 2008 40 commits
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Ingo Molnar authored
code cleanups: errors lines of code errors/KLOC arch/x86/kernel/pci-gart_64.c 183 748 244.6 arch/x86/kernel/pci-gart_64.c 0 790 0 Signed-off-by:Ingo Molnar <mingo@elte.hu> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de>
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Ingo Molnar authored
manually clean up some of the damage that lindent caused. (this is a separate commit so that in the unlikely case of a typo we can bisect it down to the manual edits.) Signed-off-by:
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Ingo Molnar authored
lindent these files: errors lines of code errors/KLOC arch/x86/math-emu/ 2236 9424 237.2 arch/x86/math-emu/ 128 8706 14.7 no other changes. No code changed: text data bss dec hex filename 5589802 612739 3833856 10036397 9924ad vmlinux.before 5589802 612739 3833856 10036397 9924ad vmlinux.after the intent of this patch is to ease the automated tracking of kernel code quality - it's just much easier for us to maintain it if every file in arch/x86 is supposed to be clean. NOTE: it is a known problem of lindent that it causes some style damage of its own, but it's a safe tool (well, except for the gcc array range initializers extension), so we did the bulk of the changes via lindent, and did the manual fixups in a followup patch. the resulting math-emu code has been tested by Thomas Gleixner on a real 386 DX CPU as well, and it works fine. Signed-off-by: -
Ingo Molnar authored
lindent the mach-voyager files to get rid of more than 300 style errors: errors lines of code errors/KLOC arch/x86/mach-voyager/ [old] 409 3729 109.6 arch/x86/mach-voyager/ [new] 71 3678 19.3 Signed-off-by: -
Ingo Molnar authored
clean up arch/x86/kernel/aperture_64.c printk()s. Signed-off-by:
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Ingo Molnar authored
whitespace cleanup. No code changed: text data bss dec hex filename 2080 76 4 2160 870 aperture_64.o.before 2080 76 4 2160 870 aperture_64.o.after errors lines of code errors/KLOC arch/x86/kernel/aperture_64.c 114 299 381.2 arch/x86/kernel/aperture_64.c 0 315 0 Signed-off-by: -
Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style cleanup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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Thomas Gleixner authored
White space and coding style clenaup. Signed-off-by:
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H. Peter Anvin authored
asm/cpufeature.h was already almost unified; this completes the job. Signed-off-by:
H. Peter Anvin <hpa@zytor.com> Signed-off-by:
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H. Peter Anvin authored
Create <asm/asm.h>, with common definitions suitable for assembly unification. Signed-off-by:
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Hiroshi Shimamoto authored
local_irq_enable() is missing after sched_clock_idle_wakeup_event(). Signed-off-by:
Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by:
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Ingo Molnar authored
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:
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Guillaume Chazarain authored
scale the sched_clock() cyc_2_nsec scaling factor according to CPU frequency changes. [ mingo@elte.hu: simplified it and fixed it for SMP. ] Signed-off-by:
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Roland McGrath authored
cf http://lkml.org/lkml/2007/10/3/41 To summarize: on Linux, SA_ONSTACK decides whether you are already on the signal stack based on the value of the SP at the time of a signal. If you are not already inside the range, you are not "on the signal stack" and so the new signal handler frame starts over at the base of the signal stack. sigaltstack (and sigstack before it) was invented in BSD. There, the SA_ONSTACK behavior has always been different. It uses a kernel state flag to decide, rather than the SP value. When you first take an SA_ONSTACK signal and switch to the alternate signal stack, it sets the SS_ONSTACK flag in the thread's sigaltstack state in the kernel. Thereafter you are "on the signal stack" and don't switch SP before pushing a handler frame no matter what the SP value is. Only when you sigreturn from the original handler context do you clear the SS_ONSTACK flag so that a new handler frame will start over at the base of the alternate signal stack. The undesireable effect of the Linux behavior is that an overflow of the alternate signal stack can not only go undetected, but lead to a ring buffer effect of clobbering the original handler frame at the base of the signal stack for each successive signal that comes just after the overflow. This is what Shi Weihua's test case demonstrates. Normally this does not come up because of the signal mask, but the test case uses SA_NODEFER for its SIGSEGV handler. The other subtle part of the existing Linux semantics is that a simple longjmp out of a signal handler serves to take you off the signal stack in a safe and reliable fashion without having used sigreturn (nor having just returned from the handler normally, which means the same). After the longjmp (or even informal stack switching not via any proper libc or kernel interface), the alternate signal stack stands ready to be used again. A paranoid program would allocate a PROT_NONE red zone around its alternate signal stack. Then a small overflow would trigger a SIGSEGV in handler setup, and be fatal (core dump) whether or not SIGSEGV is blocked. As with thread stack red zones, that cannot catch all overflows (or underflows). e.g., a local array as large as page size allocated in a function called from a handler, but not actually touched before more calls push more stack, could cause an overflow that silently pushes into some unrelated allocated pages. The BSD behavior does not do anything in particular about overflow. But it does at least avoid the wraparound or "ring buffer effect", so you'll just get a straightforward all-out overflow down your address space past the low end of the alternate signal stack. I don't know what the BSD behavior is for longjmp out of an SA_ONSTACK handler. The POSIX wording relating to sigaltstack is pretty minimal. I don't think it speaks to this issue one way or another. (The program that overflows its stack is clearly in undefined behavior territory of one sort or another anyhow.) Given the longjmp issue and the potential for highly subtle complications in existing programs relying on this in arcane ways deep in their code, I am very dubious about changing the behavior to the BSD style persistent flag. I think Shi Weihua's patches have a similar effect by tracking the SP used in the last handler setup. I think it would be sensible for the signal handler setup code to detect when it would itself be causing a stack overflow. Maybe something like the following patch (untested). This issue exists in the same way on all machines, so ideally they would all do a similar check. When it's the handler function itself or its callees that cause the overflow, rather than the signal handler frame setup alone crossing the boundary, this still won't help. But I don't see any way to distinguish that from the valid longjmp case. Signed-off-by:
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Ingo Molnar authored
add the DMI strings provided by Islam Amer <pharon@gmail.com>, for the Compaq Presario V6000 (Quanta/30B7). Signed-off-by:
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Ingo Molnar authored
make io_delay=0xed the default. This frees up port 0x80 which is a debug port on some machines and locks up certain laptops. Testing only for now. Try the io_delay=0x80 boot option if this does not work for you. Signed-off-by:
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Ingo Molnar authored
various changes to the in_p/out_p delay details: - add the io_delay=none method - make each method selectable from the kernel config - simplify the delay code a bit by getting rid of an indirect function call - add the /proc/sys/kernel/io_delay_type sysctl - change 'io_delay=standard|alternate' to io_delay=0x80 and io_delay=0xed - make the io delay config not depend on CONFIG_DEBUG_KERNEL Signed-off-by:
"David P. Reed" <dpreed@reed.com>
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Rene Herman authored
x86: provide a DMI based port 0x80 I/O delay override. Certain (HP) laptops experience trouble from our port 0x80 I/O delay writes. This patch provides for a DMI based switch to the "alternate diagnostic port" 0xed (as used by some BIOSes as well) for these. David P. Reed confirmed that port 0xed works for him and provides a proper delay. The symptoms of _not_ working are a hanging machine, with "hwclock" use being a direct trigger. Earlier versions of this attempted to simply use udelay(2), with the 2 being a value tested to be a nicely conservative upper-bound with help from many on the linux-kernel mailinglist but that approach has two problems. First, pre-loops_per_jiffy calibration (which is post PIT init while some implementations of the PIT are actually one of the historically problematic devices that need the delay) udelay() isn't particularly well-defined. We could initialise loops_per_jiffy conservatively (and based on CPU family so as to not unduly delay old machines) which would sort of work, but... Second, delaying isn't the only effect that a write to port 0x80 has. It's also a PCI posting barrier which some devices may be explicitly or implicitly relying on. Alan Cox did a survey and found evidence that additionally some drivers may be racy on SMP without the bus locking outb. Switching to an inb() makes the timing too unpredictable and as such, this DMI based switch should be the safest approach for now. Any more invasive changes should get more rigid testing first. It's moreover only very few machines with the problem and a DMI based hack seems to fit that situation. This also introduces a command-line parameter "io_delay" to override the DMI based choice again: io_delay=<standard|alternate> where "standard" means using the standard port 0x80 and "alternate" port 0xed. This retains the udelay method as a config (CONFIG_UDELAY_IO_DELAY) and command-line ("io_delay=udelay") choice for testing purposes as well. This does not change the io_delay() in the boot code which is using the same port 0x80 I/O delay but those do not appear to be a problem as David P. Reed reported the problem was already gone after using the udelay version. He moreover reported that booting with "acpi=off" also fixed things and seeing as how ACPI isn't touched until after this DMI based I/O port switch I believe it's safe to leave the ones in the boot code be. The DMI strings from David's HP Pavilion dv9000z are in there already and we need to get/verify the DMI info from other machines with the problem, notably the HP Pavilion dv6000z. This patch is partly based on earlier patches from Pavel Machek and David P. Reed. Signed-off-by:Rene Herman <rene.herman@gmail.com> Signed-off-by:
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Mike Galbraith authored
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:
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Rafael J. Wysocki authored
Document the fact that __save_processor_state() has to save all CPU registers referred to by the kernel in case a different kernel is used to load and restore a hibernation image containing it. Sigend-off-by:
Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by:
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Sam Ravnborg authored
Michael Opdenacker reported: For backward compatibility with earlier (< 2.6.24) kernels, arch/i386/boot/bzImage or arch/x86_64/boot/bzImage symbolic links to arch/x86/boot/bzImage are created when you build an x86 kernel. The arch/i386 or arch/x86_64 directories are then created for this only purpose. Issue: these generated directories and symbolic links are *not cleaned up* when you run "make mrproper" (and thus "make distclean"). This disturbs the production of patches, because the source tree is left with generated files and directories. Sam has an alternative fix: The directory is killed during make clean as opposed to make mrproper. Reported-by:
Michael Opdenacker <michael-lists@free-electrons.com> Signed-off-by:
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Venki Pallipadi authored
Current idle time in kstat is based on jiffies and is coarse grained. tick_sched.idle_sleeptime is making some attempt to keep track of idle time in a fine grained manner. But, it is not handling the time spent in interrupts fully. Make tick_sched.idle_sleeptime accurate with respect to time spent on handling interrupts and also add tick_sched.idle_lastupdate, which keeps track of last time when idle_sleeptime was updated. This statistics will be crucial for cpufreq-ondemand governor, which can shed some conservative gaurd band that is uses today while setting the frequency. The ondemand changes that uses the exact idle time is coming soon. Signed-off-by:
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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john stultz authored
I recently noticed on one of my boxes that when synched with an NTP server, the drift value reported for the system was ~283ppm. While in some cases, clock hardware can be that bad, it struck me as unusual as the system was using the acpi_pm clocksource, which is one of the more trustworthy and accurate clocksources on x86 hardware. I brought up another system and let it sync to the same NTP server, and I noticed a similar 280some ppm drift. In looking at the code, I found that the acpi_pm's constant frequency was being computed correctly at boot-up, however once the system was up, even without the ntp daemon running, the clocksource's frequency was being modified by the clocksource_adjust() function. Digging deeper, I realized that in the code that keeps track of how much the clocksource is skewing from the ntp desired time, we were using different lengths to establish how long an time interval was. The clocksource was being setup with the following interval: NTP_INTERVAL_LENGTH = NSEC_PER_SEC/NTP_INTERVAL_FREQ While the ntp code was using the tick_length_base value: tick_length_base ~= (tick_usec * NSEC_PER_USEC * USER_HZ) /NTP_INTERVAL_FREQ The subtle difference is: (tick_usec * NSEC_PER_USEC * USER_HZ) != NSEC_PER_SEC This difference in calculation was causing the clocksource correction code to apply a correction factor to the clocksource so the two intervals were the same, however this results in the actual frequency of the clocksource to be made incorrect. I believe this difference would affect all clocksources, although to differing degrees depending on the clocksource resolution. The issue was introduced when my HZ free ntp patch landed in 2.6.21-rc1, so my apologies for the mistake, and for not noticing it until now. The following patch, corrects the clocksource's initialization code so it uses the same interval length as the code in ntp.c. After applying this patch, the drift value for the same system went from ~283ppm to only 2.635ppm. I believe this patch to be good, however it does affect all arches and I've only tested on x86, so some caution is advised. I do think it would be a likely candidate for a stable 2.6.24.x release. Any thoughts or feedback would be appreciated. Signed-off-by:
John Stultz <johnstul@us.ibm.com> Signed-off-by:
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Balaji Rao authored
Looks like IRQ 31 is assigned to timer 3, even without the patch! I wonder who wrote the number 31. But the manual says that it is zero by default. I think we should check whether the timer has been allocated an IRQ before proceeding to assign one to it. Here is a patch that does this. Signed-off-by:
Balaji Rao <balajirrao@gmail.com> Tested-by:
Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by:
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Balaji Rao authored
The userspace API for the HPET (see Documentation/hpet.txt) did not work. The HPET_IE_ON ioctl was failing as there was no IRQ assigned to the timer device. This patch fixes it by allocating IRQs to timer blocks in the HPET. arch/x86/kernel/hpet.c | 13 +++++-------- drivers/char/hpet.c | 45 ++++++++++++++++++++++++++++++++++++++------- include/linux/hpet.h | 2 +- 3 files changed, 44 insertions(+), 16 deletions(-) Signed-off-by:
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Ingo Molnar authored
detect zero event-device multiplicators - they then cause division-by-zero crashes if a clockevent has been initialized incorrectly. Signed-off-by:
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Thomas Gleixner authored
The following scenario might leave PIT as a disfunctional clock source: PIT is registered as clocksource PM_TIMER is registered as clocksource and enables highres/dyntick mode PIT is switched to oneshot mode -> now the readout of PIT is bogus, but the user might select PIT via the sysfs override, which would break the box as the time readout is unusable. Unregister the PIT clocksource when the PIT clock event device is switched into shutdown / oneshot mode. Signed-off-by: -
Thomas Gleixner authored
On x86 the PIT might become an unusable clocksource. Add an unregister function to provide a possibilty to remove the PIT from the list of available clock sources. Signed-off-by:
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Thomas Gleixner authored
PIT clocksource is registered unconditionally even when HPET is enabled or when PIT is replaced by the local APIC timer. In both cases PIT can not be used as it is stopped and the readout would be stale. Prevent registering PIT in those cases. patch depends on: x86: offer is_hpet_enabled() on !CONFIG_HPET_TIMER too Signed-off-by:
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Ingo Molnar authored
offer is_hpet_enabled() on !CONFIG_HPET_TIMER too. Signed-off-by:
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Andi Kleen authored
This way it checks if the clocks are synchronized between CPUs too. This might be able to detect slowly drifting TSCs which only go wrong over longer time. Signed-off-by:
Andi Kleen <ak@suse.de> Signed-off-by:
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Parag Warudkar authored
clocksource_watchdog can use a deferrable timer - reduces wakeups from idle per second. Signed-off-by:
Parag Warudkar <parag.warudkar@gmail.com> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by:
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Geert Uytterhoeven authored
- getnstimeofday() was just a wrapper around __get_realtime_clock_ts() - Replace calls to __get_realtime_clock_ts() by calls to getnstimeofday() - Fix bogus reference to get_realtime_clock_ts(), which never existed Signed-off-by:
Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by:
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Atsushi Nemoto authored
Signed-off-by:
Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by:
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