From: Steven Rostedt (Red Hat) Date: Tue, 11 Feb 2014 18:38:54 +0000 (-0500) Subject: ring-buffer: Fix first commit on sub-buffer having non-zero delta X-Git-Tag: v3.2.56~97 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b52b81c22aca6ce4a38015ec54911ede7ab563bc;p=pandora-kernel.git ring-buffer: Fix first commit on sub-buffer having non-zero delta commit d651aa1d68a2f0a7ee65697b04c6a92f8c0a12f2 upstream. Each sub-buffer (buffer page) has a full 64 bit timestamp. The events on that page use a 27 bit delta against that timestamp in order to save on bits written to the ring buffer. If the time between events is larger than what the 27 bits can hold, a "time extend" event is added to hold the entire 64 bit timestamp again and the events after that hold a delta from that timestamp. As a "time extend" is always paired with an event, it is logical to just allocate the event with the time extend, to make things a bit more efficient. Unfortunately, when the pairing code was written, it removed the "delta = 0" from the first commit on a page, causing the events on the page to be slightly skewed. Fixes: 69d1b839f7ee "ring-buffer: Bind time extend and data events together" Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed