| Message ID | 20221215151816.19956-1-prarit@redhat.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Len Brown |
| Headers | show |
| Series | turbostat.c: Fix /dev/cpu_dma_latency warnings | expand |
diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8 index c7b26a3603af..3e1a4c4be001 100644 --- a/tools/power/x86/turbostat/turbostat.8 +++ b/tools/power/x86/turbostat/turbostat.8 @@ -344,6 +344,8 @@ Alternatively, non-root users can be enabled to run turbostat this way: # chmod +r /dev/cpu/*/msr +# chmod +r /dev/cpu_dma_latency + .B "turbostat " reads hardware counters, but doesn't write them. So it will not interfere with the OS or other programs, including diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index aba460410dbd..fef76ed294fc 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -5476,13 +5476,13 @@ void print_dev_latency(void) fd = open(path, O_RDONLY); if (fd < 0) { - warn("fopen %s\n", path); + warn("open failed, try chmod +r %s\n", path); return; } retval = read(fd, (void *)&value, sizeof(int)); if (retval != sizeof(int)) { - warn("read %s\n", path); + warn("read failed %s\n", path); close(fd); return; }
When running as non-root the following error is seen in turbostat: turbostat: fopen /dev/cpu_dma_latency : Permission denied turbostat and the man page have information on how to avoid other permission errors, so these can be fixed the same way. Provide better /dev/cpu_dma_latency warnings that provide instructions on how to avoid the error, and update the man page. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: linux-pm@vger.kernel.org --- tools/power/x86/turbostat/turbostat.8 | 2 ++ tools/power/x86/turbostat/turbostat.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-)