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author | neel <neel@FreeBSD.org> | 2010-03-24 04:52:15 +0000 |
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committer | neel <neel@FreeBSD.org> | 2010-03-24 04:52:15 +0000 |
commit | 3f8aee1ae510ea3ad4700cbde1bafe934feb7558 (patch) | |
tree | d9731e9a4a3ee467f25e546e73452075b391ffb5 /sys/mips | |
parent | 32325226c5ca5fed0d19cc1a6a94ae7e43675a4c (diff) | |
download | FreeBSD-src-3f8aee1ae510ea3ad4700cbde1bafe934feb7558.zip FreeBSD-src-3f8aee1ae510ea3ad4700cbde1bafe934feb7558.tar.gz |
Fix periodic "t_delta 16.01359db7eb5eb3c0 too long" messages on the console by
accounting for the "lost time" between when the timer interrupt fired
and when clock_intr() actually started executing.
Diffstat (limited to 'sys/mips')
-rw-r--r-- | sys/mips/mips/tick.c | 53 |
1 files changed, 36 insertions, 17 deletions
diff --git a/sys/mips/mips/tick.c b/sys/mips/mips/tick.c index b83d83f..60b3511 100644 --- a/sys/mips/mips/tick.c +++ b/sys/mips/mips/tick.c @@ -63,17 +63,14 @@ static uint64_t cycles_per_hz, cycles_per_stathz, cycles_per_profhz; static u_int32_t counter_upper = 0; static u_int32_t counter_lower_last = 0; -struct clk_ticks -{ +struct clk_ticks { u_long hard_ticks; u_long stat_ticks; u_long prof_ticks; - /* - * pad for cache line alignment of pcpu info - * cache-line-size - number of used bytes - */ - char pad[32-(3*sizeof (u_long))]; -} static pcpu_ticks[MAXCPU]; + uint32_t compare_ticks; +} __aligned(CACHE_LINE_SIZE); + +static struct clk_ticks pcpu_ticks[MAXCPU]; /* * Device methods @@ -260,25 +257,47 @@ clock_intr(void *arg) { struct clk_ticks *cpu_ticks; struct trapframe *tf; - uint32_t ltick; + uint32_t count, compare, delta; + + cpu_ticks = &pcpu_ticks[PCPU_GET(cpuid)]; + /* * Set next clock edge. */ - ltick = mips_rd_count(); - mips_wr_compare(ltick + cycles_per_tick); - cpu_ticks = &pcpu_ticks[PCPU_GET(cpuid)]; + count = mips_rd_count(); + compare = cpu_ticks->compare_ticks; + cpu_ticks->compare_ticks = count + cycles_per_tick; + mips_wr_compare(cpu_ticks->compare_ticks); critical_enter(); - if (ltick < counter_lower_last) { + if (count < counter_lower_last) { counter_upper++; - counter_lower_last = ltick; + counter_lower_last = count; } /* * Magic. Setting up with an arg of NULL means we get passed tf. */ tf = (struct trapframe *)arg; + delta = cycles_per_tick; + + /* + * Account for the "lost time" between when the timer interrupt fired + * and when 'clock_intr' actually started executing. + */ + delta += count - compare; + + /* + * If the COUNT and COMPARE registers are no longer in sync then make + * up some reasonable value for the 'delta'. + * + * This could happen, for e.g., after we resume normal operations after + * exiting the debugger. + */ + if (delta > cycles_per_hz) + delta = cycles_per_hz; + /* Fire hardclock at hz. */ - cpu_ticks->hard_ticks += cycles_per_tick; + cpu_ticks->hard_ticks += delta; if (cpu_ticks->hard_ticks >= cycles_per_hz) { cpu_ticks->hard_ticks -= cycles_per_hz; if (PCPU_GET(cpuid) == 0) @@ -288,14 +307,14 @@ clock_intr(void *arg) } /* Fire statclock at stathz. */ - cpu_ticks->stat_ticks += cycles_per_tick; + cpu_ticks->stat_ticks += delta; if (cpu_ticks->stat_ticks >= cycles_per_stathz) { cpu_ticks->stat_ticks -= cycles_per_stathz; statclock(USERMODE(tf->sr)); } /* Fire profclock at profhz, but only when needed. */ - cpu_ticks->prof_ticks += cycles_per_tick; + cpu_ticks->prof_ticks += delta; if (cpu_ticks->prof_ticks >= cycles_per_profhz) { cpu_ticks->prof_ticks -= cycles_per_profhz; if (profprocs != 0) |