Re: perf-core build fails on powerpc

[John Garry]

On 13/03/2018 20:10, Sukadev Bhattiprolu wrote:

+

> John Garry [john.garry@xxxxxxxxxx] wrote:
> > On 13/03/2018 19:17, Sukadev Bhattiprolu wrote:
> > > Building perf on Powerpc seems broken when using Arnaldo's perf/core branch
> > > with HEAD as:
> > >
> > >     1b442ed ("perf test: Fix exit code for record+probe_libc_inet_pton.sh")
> > >
> > > It maybe related to this commit:
> > >
> > > 	commit d596299
> > > 	Author: John Garry <john.garry@xxxxxxxxxx>
> > > 	Date:   Thu Mar 8 18:58:29 2018 +0800
> > >
> > > 	    perf vendor events: Add support for pmu events vendor subdirectory
> > >
> > > Reverting this hunk from tools/perf/pmu-events/jevents.c, seems to fix the
> > > problem for me.
>
> Hi John,
>
> I have an xfs file system which seems to have d_type == DT_UNKNOWN for all
> entries in 'tools/perf/pmu-events/arch/power8'! readdir(3) says ->d_type
> may not be supported by all file systems.
>
> Not relying on ->d_type seems to fix it:

Hi Sukadev,

Thanks for debugging this. Jiri Olsa (cc'ed) warned me on this, so I did 
add the check for d_type == DT_UNKNOWN.

But, if all files have d_type == DT_UNKNOWN, you're code would from 
visual observation look to be same as mine (apart from check for '.' or 
'..' filename, which I would say is already covered by stat() and 
S_ISDIR()). Or is d_type value just unreliable?

Much appreciated,
John

> @@ -873,26 +879,26 @@ static int is_leaf_dir(const char *fpath)
>                 return 0;
>
>         while ((dir = readdir(d)) != NULL) {
> -               if (dir->d_type == DT_DIR && dir->d_name[0] != '.') {
> -                       res = 0;
> -                       break;
> -               } else if (dir->d_type == DT_UNKNOWN) {
> -                       char path[PATH_MAX];
> -                       struct stat st;
> +               char path[PATH_MAX];
> +               struct stat st;
>
> -                       sprintf(path, "%s/%s", fpath, dir->d_name);
> -                       if (stat(path, &st))
> -                               break;
> +               if (strcmp(dir->d_name, ".") == 0 ||
> +                               strcmp(dir->d_name, "..") == 0)
> +                       continue;
>
> -                       if (S_ISDIR(st.st_mode)) {
> -                               res = 0;
> -                               break;
> -                       }
> +               sprintf(path, "%s/%s", fpath, dir->d_name);
> +               if (stat(path, &st))
> +                       break;
> +
> +               if (S_ISDIR(st.st_mode)) {
> +                       res = 0;
> +                       break;