git: systimer: Fix statclock() intr% counting for i8254 interrupt cputimer

[Sepherosa Ziehau <sephe@xxxxxxxxxxxxxxxxxxxxxxx>]

commit 96d52ac818036eee9591e612e829d78217bd2d3b
Author: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date:   Thu Apr 14 13:10:55 2011 +0800

    systimer: Fix statclock() intr% counting for i8254 interrupt cputimer
    
    If i8254 is used as interrupt cputimer, it will send IPIs to APs to get
    statclock() called.  In order to detect fast interrupt, statclock()
    tests gd_intr_nesting_level to see whether it should bump intr% or not,
    however, during IPI processing, gd_intr_nesting_level is bumped up, which
    tricks statclock() to believe that intr% should be incremented.  This
    usually leads to 100% interrupt time on APs reported by utilities like
    systat(1).  To solve this problem:
    
    - Pass in_ipi to systimer functions to indicate whether the functions are
      called during IPI processing or not.
    - In statclock(): if it is called during IPI processing, using
      (gd_intr_nesting_level - 1) to test whether intr% should be incremented
      or not.
    
    Additional cleanup:
    - Make systimer_init_*() interface stricter, by using "systimer_func_t"
      instead of "void *"

Summary of changes:
 sys/cpu/i386/include/cpu.h     |    2 +-
 sys/cpu/x86_64/include/cpu.h   |    2 +-
 sys/kern/kern_clock.c          |   26 ++++++++++++++++++--------
 sys/kern/kern_intr.c           |    8 +++++---
 sys/kern/kern_poll.c           |    5 +++--
 sys/kern/kern_systimer.c       |   13 +++++++------
 sys/kern/kern_time.c           |    3 ++-
 sys/net/dummynet/ip_dummynet.c |    5 +++--
 sys/net/if_poll.c              |   12 +++++++-----
 sys/platform/pc32/isa/clock.c  |    2 +-
 sys/platform/pc64/isa/clock.c  |    2 +-
 sys/sys/systimer.h             |   13 ++++++-------
 12 files changed, 55 insertions(+), 38 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/96d52ac818036eee9591e612e829d78217bd2d3b


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