From: Balbir Singh Hi, Andrew, While testing on ppc64, I found that taskstats could return incorrect data. The same code worked fine on x86. Thanks, Balbir Singh, Linux Technology Center, IBM Software Labs Description of the patch ------------------------ tsk->utime and tsk->stime are of type cputime_t. Explicitly converting from cputime to nanoseconds does not work on all platforms. Use the cputime API for conversion. This makes the code more portable and returns correct data on ppc64. This patch has been tested on x86 and ppc64. Signed-off-by: Balbir Singh Cc: Shailabh Nagar Cc: Jes Sorensen Cc: Peter Chubb Cc: Erich Focht Cc: Levent Serinol Cc: Jay Lan Signed-off-by: Andrew Morton --- kernel/delayacct.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletion(-) diff -puN kernel/delayacct.c~per-task-delay-accounting-delay-accounting-usage-of-taskstats-interface-use-portable-cputime-api-in-__delayacct_add_tsk kernel/delayacct.c --- devel/kernel/delayacct.c~per-task-delay-accounting-delay-accounting-usage-of-taskstats-interface-use-portable-cputime-api-in-__delayacct_add_tsk 2006-05-11 09:37:07.000000000 -0700 +++ devel-akpm/kernel/delayacct.c 2006-05-11 09:37:07.000000000 -0700 @@ -112,7 +112,8 @@ int __delayacct_add_tsk(struct taskstats unsigned long t1,t2,t3; tmp = (s64)d->cpu_run_real_total; - tmp += (u64)(tsk->utime + tsk->stime) * TICK_NSEC; + cputime_to_timespec(tsk->utime + tsk->stime, &ts); + tmp += timespec_to_ns(&ts); d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; /* _