From: Steven Rostedt Date: Wed, 29 Apr 2009 17:43:37 +0000 (-0400) Subject: ring-buffer: add counters for commit overrun and nmi dropped entries X-Git-Tag: v2.6.31-rc1~401^2~92 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f0d2c681ac0a85142fc8abe65fc33fcad35cb9b7;p=pandora-kernel.git ring-buffer: add counters for commit overrun and nmi dropped entries The WARN_ON in the ring buffer when a commit is preempted and the buffer is filled by preceding writes can happen in normal operations. The WARN_ON makes it look like a bug, not to mention, because it does not stop tracing and calls printk which can also recurse, this is prone to deadlock (the WARN_ON is not in a position to recurse). This patch removes the WARN_ON and replaces it with a counter that can be retrieved by a tracer. This counter is called commit_overrun. While at it, I added a nmi_dropped counter to count any time an NMI entry is dropped because the NMI could not take the spinlock. [ Impact: prevent deadlock by printing normal case warning ] Signed-off-by: Steven Rostedt --- Reading git-diff-tree failed