1. 19 9月, 2008 12 次提交
  2. 14 9月, 2008 3 次提交
  3. 10 9月, 2008 3 次提交
    • F
    • F
    • P
      x86: fix memmap=exactmap boot argument · d6be118a
      Prarit Bhargava 提交于
      When using kdump modifying the e820 map is yielding strange results.
      
      For example starting with
      
       BIOS-provided physical RAM map:
       BIOS-e820: 0000000000000100 - 0000000000093400 (usable)
       BIOS-e820: 0000000000093400 - 00000000000a0000 (reserved)
       BIOS-e820: 0000000000100000 - 000000003fee0000 (usable)
       BIOS-e820: 000000003fee0000 - 000000003fef3000 (ACPI data)
       BIOS-e820: 000000003fef3000 - 000000003ff80000 (ACPI NVS)
       BIOS-e820: 000000003ff80000 - 0000000040000000 (reserved)
       BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
       BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
       BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
       BIOS-e820: 00000000ff000000 - 0000000100000000 (reserved)
      
      and booting with args
      
      memmap=exactmap memmap=640K@0K memmap=5228K@16384K memmap=125188K@22252K memmap=76K#1047424K memmap=564K#1047500K
      
      resulted in:
      
       user-defined physical RAM map:
       user: 0000000000000000 - 0000000000093400 (usable)
       user: 0000000000093400 - 00000000000a0000 (reserved)
       user: 0000000000100000 - 000000003fee0000 (usable)
       user: 000000003fee0000 - 000000003fef3000 (ACPI data)
       user: 000000003fef3000 - 000000003ff80000 (ACPI NVS)
       user: 000000003ff80000 - 0000000040000000 (reserved)
       user: 00000000e0000000 - 00000000f0000000 (reserved)
       user: 00000000fec00000 - 00000000fec10000 (reserved)
       user: 00000000fee00000 - 00000000fee01000 (reserved)
       user: 00000000ff000000 - 0000000100000000 (reserved)
      
      But should have resulted in:
      
       user-defined physical RAM map:
       user: 0000000000000000 - 00000000000a0000 (usable)
       user: 0000000001000000 - 000000000151b000 (usable)
       user: 00000000015bb000 - 0000000008ffc000 (usable)
       user: 000000003fee0000 - 000000003ff80000 (ACPI data)
      
      This is happening because of an improper usage of strcmp() in the
      e820 parsing code.  The strcmp() always returns !0 and never resets the
      value for e820.nr_map and returns an incorrect user-defined map.
      
      This patch fixes the problem.
      Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      d6be118a
  4. 08 9月, 2008 3 次提交
  5. 07 9月, 2008 2 次提交
  6. 06 9月, 2008 8 次提交
  7. 05 9月, 2008 2 次提交
  8. 04 9月, 2008 2 次提交
  9. 03 9月, 2008 2 次提交
    • L
      Split up PIT part of TSC calibration from native_calibrate_tsc · ec0c15af
      Linus Torvalds 提交于
      The TSC calibration function is still very complicated, but this makes
      it at least a little bit less so by moving the PIT part out into a
      helper function of its own.
      Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
      Signed-of-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ec0c15af
    • T
      [x86] Fix TSC calibration issues · fbb16e24
      Thomas Gleixner 提交于
      Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
      An ancient laptop of mine started throwing errors from b43legacy when
      I started using 2.6.27 on it. This has been bisected to commit bfc0f594
      "x86: merge tsc calibration".
      
      The unification of the TSC code adopted mostly the 64bit code, which
      prefers PMTIMER/HPET over the PIT calibration.
      
      Larrys system has an AMD K6 CPU. Such systems are known to have
      PMTIMER incarnations which run at double speed. This results in a
      miscalibration of the TSC by factor 0.5. So the resulting calibrated
      CPU/TSC speed is half of the real CPU speed, which means that the TSC
      based delay loop will run half the time it should run. That might
      explain why the b43legacy driver went berserk.
      
      On the other hand we know about systems, where the PIT based
      calibration results in random crap due to heavy SMI/SMM
      disturbance. On those systems the PMTIMER/HPET based calibration logic
      with SMI detection shows better results.
      
      According to Alok also virtualized systems suffer from the PIT
      calibration method.
      
      The solution is to use a more wreckage aware aproach than the current
      either/or decision.
      
      1) reimplement the retry loop which was dropped from the 32bit code
      during the merge. It repeats the calibration and selects the lowest
      frequency value as this is probably the closest estimate to the real
      frequency
      
      2) Monitor the delta of the TSC values in the delay loop which waits
      for the PIT counter to reach zero. If the maximum value is
      significantly different from the minimum, then we have a pretty safe
      indicator that the loop was disturbed by an SMI.
      
      3) keep the pmtimer/hpet reference as a backup solution for systems
      where the SMI disturbance is a permanent point of failure for PIT
      based calibration
      
      4) do the loop iteration for both methods, record the lowest value and
      decide after all iterations finished.
      
      5) Set a clear preference to PIT based calibration when the result
      makes sense.
      
      The implementation does the reference calibration based on
      HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
      but keeps separate TSC values to ensure the "independency" of the
      resulting calibration values.
      
      Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
      (affected machine with a double speed pmtimer which I grabbed out of
      the dump), Pentium class machines and AMD/Intel 64 bit boxen.
      Bisected-by: NLarry Finger <Larry.Finger@lwfinger.net>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fbb16e24
  10. 26 8月, 2008 3 次提交