Messages in this thread Patch in this message |  | | | Date | Thu, 27 Nov 2008 01:36:45 +1030 | | From | Ron <> | | Subject | [patch] fix for sched_clock() when using jiffies |
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Hi,
I'm in the process of updating a port for an ARM based chip we've been working on, from 2.6.22-rc4'ish to the current HEAD of Linus' tree, and I started seeing the following:
[ 0.000000] PID hash table entries: 512 (order: 9, 2048 bytes) [42949372.970000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes) The reason appears to be that printk_clock() has been replaced with a call to cpu_clock, which in our case currently falls back to the default (weak) implementation of sched_clock() that uses jiffies -- but doesn't account for the initial offset of the jiffy count. The following simple patch fixes it for me, in line with what printk_clock used to do.
Cheers, Ron
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index 8178724..d76814e 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -37,7 +37,7 @@ */ unsigned long long __attribute__((weak)) sched_clock(void) { - return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ); + return (unsigned long long)(jiffies - INITIAL_JIFFIES) * (NSEC_PER_SEC / HZ); }
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