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authorSteven Rostedt <rostedt@goodmis.org>2008-11-12 17:52:36 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-13 03:49:21 -0500
commita94c80e78bc9f4493ffc25a02d5d7bcd93c399d0 (patch)
tree7bccb9ade6edc033887db7c6f9f7157c5d612e3c /Documentation/ftrace.txt
parent24de38620dd3504782c90c0892eef888d0c351e9 (diff)
ftrace: rename trace_entries to buffer_size_kb
Impact: rename of debugfs file trace_entries to buffer_size_kb The original ftrace had fixed size entries, and the number of entries was shown and modified via the file called trace_entries. By converting to the unified trace buffer, we now allow for variable size entries which makes the meaning of trace_entries pointless. Since trace_size might be confused to the size of the trace, this patch names it "buffer_size_kb" (thanks to Arjan van de Ven for this idea). [ mingo@elte.hu: changed from buffer_size to buffer_size_kb ] ( Note, the units are still bytes - the next patch changes that, to keep the wide rename patch separate from the unit-change patch. ) Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/ftrace.txt')
-rw-r--r--Documentation/ftrace.txt18
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:
94 only be recorded if the latency is greater than 94 only be recorded if the latency is greater than
95 the value in this file. (in microseconds) 95 the value in this file. (in microseconds)
96 96
97 trace_entries: This sets or displays the number of bytes each CPU 97 buffer_size_kb: This sets or displays the number of bytes each CPU
98 buffer can hold. The tracer buffers are the same size 98 buffer can hold. The tracer buffers are the same size
99 for each CPU. The displayed number is the size of the 99 for each CPU. The displayed number is the size of the
100 CPU buffer and not total size of all buffers. The 100 CPU buffer and not total size of all buffers. The
@@ -1299,13 +1299,13 @@ trace entries
1299------------- 1299-------------
1300 1300
1301Having too much or not enough data can be troublesome in diagnosing 1301Having too much or not enough data can be troublesome in diagnosing
1302an issue in the kernel. The file trace_entries is used to modify 1302an issue in the kernel. The file buffer_size_kb is used to modify
1303the size of the internal trace buffers. The number listed 1303the size of the internal trace buffers. The number listed
1304is the number of entries that can be recorded per CPU. To know 1304is the number of entries that can be recorded per CPU. To know
1305the full size, multiply the number of possible CPUS with the 1305the full size, multiply the number of possible CPUS with the
1306number of entries. 1306number of entries.
1307 1307
1308 # cat /debug/tracing/trace_entries 1308 # cat /debug/tracing/buffer_size_kb
130965620 130965620
1310 1310
1311Note, to modify this, you must have tracing completely disabled. To do that, 1311Note, 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
1313to "nop", an EINVAL error will be returned. 1313to "nop", an EINVAL error will be returned.
1314 1314
1315 # echo nop > /debug/tracing/current_tracer 1315 # echo nop > /debug/tracing/current_tracer
1316 # echo 100000 > /debug/tracing/trace_entries 1316 # echo 100000 > /debug/tracing/buffer_size_kb
1317 # cat /debug/tracing/trace_entries 1317 # cat /debug/tracing/buffer_size_kb
1318100045 1318100045
1319 1319
1320 1320
@@ -1323,8 +1323,8 @@ are held in individual pages. It allocates the number of pages it takes
1323to fulfill the request. If more entries may fit on the last page 1323to fulfill the request. If more entries may fit on the last page
1324then they will be added. 1324then they will be added.
1325 1325
1326 # echo 1 > /debug/tracing/trace_entries 1326 # echo 1 > /debug/tracing/buffer_size_kb
1327 # cat /debug/tracing/trace_entries 1327 # cat /debug/tracing/buffer_size_kb
132885 132885
1329 1329
1330This shows us that 85 entries can fit in a single page. 1330This 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.
1332The number of pages which will be allocated is limited to a percentage 1332The number of pages which will be allocated is limited to a percentage
1333of available memory. Allocating too much will produce an error. 1333of available memory. Allocating too much will produce an error.
1334 1334
1335 # echo 1000000000000 > /debug/tracing/trace_entries 1335 # echo 1000000000000 > /debug/tracing/buffer_size_kb
1336-bash: echo: write error: Cannot allocate memory 1336-bash: echo: write error: Cannot allocate memory
1337 # cat /debug/tracing/trace_entries 1337 # cat /debug/tracing/buffer_size_kb
133885 133885
1339 1339