1. 18 3月, 2009 6 次提交
  2. 17 3月, 2009 2 次提交
    • L
      Fast TSC calibration: calculate proper frequency error bounds · 9e8912e0
      Linus Torvalds 提交于
      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: NJesper Krogh <jesper@krogh.cc>
      Cc: john stultz <johnstul@us.ibm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9e8912e0
    • L
      Fix potential fast PIT TSC calibration startup glitch · a6a80e1d
      Linus Torvalds 提交于
      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: Njohn stultz <johnstul@us.ibm.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a6a80e1d
  3. 13 3月, 2009 20 次提交
  4. 12 3月, 2009 1 次提交
  5. 11 3月, 2009 5 次提交
  6. 10 3月, 2009 1 次提交
    • D
      Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod." · 129f8ae9
      Dave Jones 提交于
      This reverts commit e088e4c9.
      
      Removing the sysfs interface for p4-clockmod was flagged as a
      regression in bug 12826.
      
      Course of action:
       - Find out the remaining causes of overheating, and fix them
         if possible. ACPI should be doing the right thing automatically.
         If it isn't, we need to fix that.
       - mark p4-clockmod ui as deprecated
       - try again with the removal in six months.
      
      It's not really feasible to printk about the deprecation, because
      it needs to happen at all the sysfs entry points, which means adding
      a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.
      Signed-off-by: NDave Jones <davej@redhat.com>
      129f8ae9
  7. 09 3月, 2009 5 次提交
    • R
      lguest: fix for CONFIG_SPARSE_IRQ=y · 6db6a5f3
      Rusty Russell 提交于
      Impact: remove lots of lguest boot WARN_ON() when CONFIG_SPARSE_IRQ=y
      
      We now need to call irq_to_desc_alloc_cpu() before
      set_irq_chip_and_handler_name(), but we can't do that from init_IRQ (no
      kmalloc available).
      
      So do it as we use interrupts instead.  Also means we only alloc for
      irqs we use, which was the intent of CONFIG_SPARSE_IRQ anyway.
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Cc: Ingo Molnar <mingo@redhat.com>
      6db6a5f3
    • R
      lguest: fix crash 'unhandled trap 13 at <native_read_msr_safe>' · cbd88c8e
      Rusty Russell 提交于
      Impact: fix lguest boot crash on modern Intel machines
      
      The code in early_init_intel does:
      
      	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
      		u64 misc_enable;
      
      		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
      
      And that rdmsr faults (not allowed from non-0 PL).  We can get around
      this by mugging the family ID part of the cpuid.  5 seems like a good
      number.
      
      Of course, this is a hack (how very lguest!).  We could just indicate
      that we don't support MSRs, or implement lguest_rdmst.
      Reported-by: NPatrick McHardy <kaber@trash.net>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      Tested-by: NPatrick McHardy <kaber@trash.net>
      cbd88c8e
    • J
      x86-32: make sure virt_addr_valid() returns false for fixmap addresses · 0feca851
      Jeremy Fitzhardinge 提交于
      I found that virt_addr_valid() was returning true for fixmap addresses.
      
      I'm not sure whether pfn_valid() is supposed to include this test,
      but there's no harm in being explicit.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      LKML-Reference: <49B166D6.2080505@goop.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0feca851
    • S
      x86 mmiotrace: fix remove_kmmio_fault_pages() · d0fc63f7
      Stuart Bennett 提交于
      Impact: fix race+crash in mmiotrace
      
      The list manipulation in remove_kmmio_fault_pages() was broken. If more
      than one consecutive kmmio_fault_page was re-added during the grace
      period between unregister_kmmio_probe() and remove_kmmio_fault_pages(),
      the list manipulation failed to remove pages from the release list.
      
      After a second grace period the pages get into rcu_free_kmmio_fault_pages()
      and raise a BUG_ON() kernel crash.
      
      The list manipulation is fixed to properly remove pages from the release
      list.
      
      This bug has been present from the very beginning of mmiotrace in the
      mainline kernel. It was introduced in 0fd0e3da ("x86: mmiotrace full
      patch, preview 1");
      
      An urgent fix for Linus. Tested by Stuart (on 32-bit) and Pekka
      (on amd and intel 64-bit systems, nouveau and nvidia proprietary).
      Signed-off-by: NStuart Bennett <stuart@freedesktop.org>
      Signed-off-by: NPekka Paalanen <pq@iki.fi>
      LKML-Reference: <20090308202135.34933feb@daedalus.pq.iki.fi>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      d0fc63f7
    • Y
      x86: fix warning about nodeid · e954ef20
      Yinghai Lu 提交于
      Impact: cleanup
      
      Ingo found there warning about nodeid with some configs.
      
      try to use for_each_online_node for non numa too. in that case
      nodeid will be 0.
      
      also move out boundary checking from setup_node_bootmem(), so
      non-numa config will not check it.
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      LKML-Reference: <49B03069.80001@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e954ef20