Messages in this thread Patch in this message | | | Date | Wed, 27 May 2009 22:34:35 GMT | From | tip-bot for Li Zefan <> | Subject | [tip:tracing/core] tracing/events: change the type of __str_loc_item to unsigned short |
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Commit-ID: b0aae68cc5508f3c2fbf728988c954db4c8b8a53 Gitweb: http://git.kernel.org/tip/b0aae68cc5508f3c2fbf728988c954db4c8b8a53 Author: Li Zefan <lizf@cn.fujitsu.com> AuthorDate: Thu, 21 May 2009 13:59:18 +0800 Committer: Frederic Weisbecker <fweisbec@gmail.com> CommitDate: Tue, 26 May 2009 00:15:21 +0200
tracing/events: change the type of __str_loc_item to unsigned short
When defining a dynamic size string, we add __str_loc_##item to the trace entry, and it stores the location of the actual string in entry->_str_data[]
'unsigned short' should be sufficient to store this information, thus we save 2 bytes per dyn-size string in the ring buffer.
[ Impact: reduce memory occupied by dyn-size strings in ring buffer ]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4A14EDB6.2050507@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
--- include/trace/ftrace.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index edb02bc..b5ff2e8 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -25,7 +25,7 @@ #define __field(type, item) type item; #undef __string -#define __string(item, src) int __str_loc_##item; +#define __string(item, src) unsigned short __str_loc_##item; #undef TP_STRUCT__entry #define TP_STRUCT__entry(args...) args
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