[lxc-devel] [PATCH] /proc/stat in lxcfs

[Serge Hallyn]

Quoting Christian Brauner (christianvanbrauner at gmail.com):
> 
> > > +        else if (sscanf(cpu_char, "%d", &cpu) != 1) {
> > 
> > This is an unorthodox (for lxc) coding style.  Could you explain
> > exactly what you're doing here?  I would expect just:
> > 
> >     if (sscanf(cpu_char, "%d", &cpu) != 1))
> >         continue;
> >     if (!cpu_in_cpuset(cpu, cpuset))
> >         continue;
> 
> Your way is the better way to do it. I adjusted and squased the PR and
> post the patch again here as well:
> 
> commit 21c3c7ace34eaf5f19074e332222d050896b5cc3
> Author: Christian Brauner <christianvanbrauner at gmail.com>
> Date:   Sun Feb 15 11:31:31 2015 +0100
> 
>     Show cpu-average in /proc/stat and start cup numbering at 0

Note, your previous patch had a signed-off-by, but this one does not.
I'll let Stéphane decide whether that's good enough :)

Thanks, Christian.

Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>

> 
> diff --git a/lxcfs.c b/lxcfs.c
> index d6fb101..d358829 100644
> --- a/lxcfs.c
> +++ b/lxcfs.c
> @@ -1642,7 +1642,7 @@ static int proc_stat_read(char *buf, size_t size, off_t offset,
>     nih_local char *cpuset = NULL;
>     char *line = NULL;
>     size_t linelen = 0, total_len = 0;
> -   int curcpu = 0;
> +   int curcpu = -1; /* cpu numbering starts at 0 */
>     FILE *f;
>  
>     if (offset)
> @@ -1662,16 +1662,21 @@ static int proc_stat_read(char *buf, size_t size, off_t offset,
>     while (getline(&line, &linelen, f) != -1) {
>         size_t l;
>         int cpu;
> +        char cpu_char[10]; /* That's a lot of cores */
>         char *c;
>  
> -       if (sscanf(line, "cpu%d", &cpu) != 1) {
> -           /* not a ^cpu line, just print it */
> +       if (sscanf(line, "cpu%9[^ ]", cpu_char) != 1) {
> +           /* not a ^cpuN line containing a number N, just print it */
>             l = snprintf(buf, size, "%s", line);
>             buf += l;
>             size -= l;
>             total_len += l;
>             continue;
>         }
> +
> +        if (sscanf(cpu_char, "%d", &cpu) != 1)
> +                continue;
> +
>         if (!cpu_in_cpuset(cpu, cpuset))
>             continue;
>         curcpu ++;
> 
> Christian



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