Messages in this thread | | | Date | Thu, 24 Sep 2009 09:51:06 -0700 | From | Andrew Morton <> | Subject | Re: [GIT PULL] cputime tree |
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On Thu, 24 Sep 2009 13:31:36 +0200 Martin Schwidefsky <schwidefsky@de.ibm.com> wrote:
> Hi Linus, > > with git commit 79741dd "idle cputime accounting" the semantic > of the stime field of the idle processes has changed. It used to > contain the amount of time the idle process has been scheduled. > Since git commit 79741dd is contains the cpu time spent in the > system by the idle process. > > This change broke the output of second field of /proc/uptime. On > systems without VIRT_CPU_ACCOUNTING the field is always zero. > The legacy output of the field is the amount of time the idle > process has been scheduled on cpu #0. It is good enough to > calculate the load on an uni-processor system, it is useless > on a multi-processor. To restore the legacy behaviour and give > meaning to the multi-processor case the best we could come up > with is to add the idle time over all cpus. That fixes uni- > processors systems and gives a defined semantic on smp. > > So please pull from 'cputime' branch of > > git://git390.marist.edu/pub/scm/linux-2.6.git cputime > > to receive the following updates: > > Michael Abbott (1): > Fix idle time field in /proc/uptime > > fs/proc/uptime.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c > index 0c10a0b..766b1d4 100644 > --- a/fs/proc/uptime.c > +++ b/fs/proc/uptime.c > @@ -4,13 +4,18 @@ > #include <linux/sched.h> > #include <linux/seq_file.h> > #include <linux/time.h> > +#include <linux/kernel_stat.h> > #include <asm/cputime.h> > > static int uptime_proc_show(struct seq_file *m, void *v) > { > struct timespec uptime; > struct timespec idle; > - cputime_t idletime = cputime_add(init_task.utime, init_task.stime); > + int i; > + cputime_t idletime = cputime_zero; > + > + for_each_possible_cpu(i) > + idletime = cputime64_add(idletime, kstat_cpu(i).cpustat.idle); > > do_posix_clock_monotonic_gettime(&uptime); > monotonic_to_bootbased(&uptime);
This is a regression fix, iirc? One which is applicable for several 2.6.x kernel versions?
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