From: Yoshihiro YUNOMAE Date: Thu, 5 Jun 2014 01:24:27 +0000 (+0900) Subject: tracing: Introduce saved_cmdlines_size file X-Git-Tag: omap-for-v3.16/fixes-against-rc1~80^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=939c7a4f04fcd2162109744e8bf88194948a6e65;p=pandora-kernel.git tracing: Introduce saved_cmdlines_size file Introduce saved_cmdlines_size file for changing the number of saved pid-comms. saved_cmdlines currently stores 128 command names using SAVED_CMDLINES, but 'no-existing processes' names are often lost in saved_cmdlines when we read the trace data. So, by introducing saved_cmdlines_size file, we can now change the 128 command names saved to something much larger if needed. When we write a value to saved_cmdlines_size, the number of the value will be stored in pid-comm list: # echo 1024 > /sys/kernel/debug/tracing/saved_cmdlines_size Here, 1024 command names can be stored. The default number is 128 and the maximum number is PID_MAX_DEFAULT (=32768 if CONFIG_BASE_SMALL is not set). So, if we want to avoid losing any command names, we need to set 32768 to saved_cmdlines_size. We can read the maximum number of the list: # cat /sys/kernel/debug/tracing/saved_cmdlines_size 128 Link: http://lkml.kernel.org/p/20140605012427.22115.16173.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE Signed-off-by: Steven Rostedt --- Reading git-diff-tree failed