3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Bo Yan byan@nvidia.com
commit 8dd33bcb7050dd6f8c1432732f930932c9d3a33e upstream.
One convenient way to erase trace is "echo > trace". However, this is currently broken if the current tracer is irqsoff tracer. This is because irqsoff tracer use max_buffer as the default trace buffer.
Set the max_buffer as the one to be cleared when it's the trace buffer currently in use.
Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com
Cc: mingo@redhat.com Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer") Signed-off-by: Bo Yan byan@nvidia.com Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- kernel/trace/trace.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3191,11 +3191,17 @@ static int tracing_open(struct inode *in /* If this file was open for write, then erase contents */ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { int cpu = tracing_get_cpu(inode); + struct trace_buffer *trace_buf = &tr->trace_buffer; + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->current_trace->print_max) + trace_buf = &tr->max_buffer; +#endif
if (cpu == RING_BUFFER_ALL_CPUS) - tracing_reset_online_cpus(&tr->trace_buffer); + tracing_reset_online_cpus(trace_buf); else - tracing_reset(&tr->trace_buffer, cpu); + tracing_reset(trace_buf, cpu); }
if (file->f_mode & FMODE_READ) {