(03/06/2013 10:49 PM), Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)"<srost...@redhat.com> > > To use the tracing snapshot feature, writing a '1' into the snapshot > file causes the snapshot buffer to be allocated if it has not already > been allocated and dose a 'swap' with the main buffer, so that the > snapshot now contains what was in the main buffer, and the main buffer > now writes to what was the snapshot buffer. > > To free the snapshot buffer, a '0' is written into the snapshot file. > > To clear the snapshot buffer, any number but a '0' or '1' is written > into the snapshot file. But if the file is not allocated it returns > -EINVAL error code. This is rather pointless. It is better just to > do nothing and return success. > > Cc: Hiraku Toyooka<hiraku.toyooka...@hitachi.com> > Signed-off-by: Steven Rostedt<rost...@goodmis.org> > ---
Acked-by: Hiraku Toyooka <hiraku.toyooka...@hitachi.com> > kernel/trace/trace.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 9e3120b..1f835a8 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -4167,8 +4167,6 @@ tracing_snapshot_write(struct file *filp, const char > __user *ubuf, size_t cnt, > default: > if (current_trace->allocated_snapshot) > tracing_reset_online_cpus(&max_tr); > - else > - ret = -EINVAL; > break; > } > > -- 1.7.10.4 . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
