diff options
Diffstat (limited to 'Documentation/ftrace.txt')
| -rw-r--r-- | Documentation/ftrace.txt | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt index 9cc4d685dde5..a1b58777839b 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/ftrace.txt @@ -94,7 +94,7 @@ of ftrace. Here is a list of some of the key files: only be recorded if the latency is greater than the value in this file. (in microseconds) - trace_entries: This sets or displays the number of bytes each CPU + buffer_size_kb: This sets or displays the number of bytes each CPU buffer can hold. The tracer buffers are the same size for each CPU. The displayed number is the size of the CPU buffer and not total size of all buffers. The @@ -1299,13 +1299,13 @@ trace entries ------------- Having too much or not enough data can be troublesome in diagnosing -an issue in the kernel. The file trace_entries is used to modify +an issue in the kernel. The file buffer_size_kb is used to modify the size of the internal trace buffers. The number listed is the number of entries that can be recorded per CPU. To know the full size, multiply the number of possible CPUS with the number of entries. - # cat /debug/tracing/trace_entries + # cat /debug/tracing/buffer_size_kb 65620 Note, to modify this, you must have tracing completely disabled. To do that, @@ -1313,8 +1313,8 @@ echo "nop" into the current_tracer. If the current_tracer is not set to "nop", an EINVAL error will be returned. # echo nop > /debug/tracing/current_tracer - # echo 100000 > /debug/tracing/trace_entries - # cat /debug/tracing/trace_entries + # echo 100000 > /debug/tracing/buffer_size_kb + # cat /debug/tracing/buffer_size_kb 100045 @@ -1323,8 +1323,8 @@ are held in individual pages. It allocates the number of pages it takes to fulfill the request. If more entries may fit on the last page then they will be added. - # echo 1 > /debug/tracing/trace_entries - # cat /debug/tracing/trace_entries + # echo 1 > /debug/tracing/buffer_size_kb + # cat /debug/tracing/buffer_size_kb 85 This shows us that 85 entries can fit in a single page. @@ -1332,8 +1332,8 @@ This shows us that 85 entries can fit in a single page. The number of pages which will be allocated is limited to a percentage of available memory. Allocating too much will produce an error. - # echo 1000000000000 > /debug/tracing/trace_entries + # echo 1000000000000 > /debug/tracing/buffer_size_kb -bash: echo: write error: Cannot allocate memory - # cat /debug/tracing/trace_entries + # cat /debug/tracing/buffer_size_kb 85 |
