From: Frederic Weisbecker Date: Sat, 17 Oct 2009 15:12:34 +0000 (+0200) Subject: perf tools: Introduce bitmask'ed additional headers X-Git-Tag: v2.6.33-rc1~399^2~187^2~19 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2ba0825075e76236d22a20decd8e2346a99faabe;p=pandora-kernel.git perf tools: Introduce bitmask'ed additional headers This provides a new set of bitmasked headers. A new field is added in the perf headers that implements a bitmap storing optional features present in the perf.data file. The layout can be pictured like this: (Usual perf headers)(Features bitmap)[Feature 0][Feature n][Feature 255] If the bit n is set, then the feature n is used in this file. They are all set in order. This brings a backward and forward compatibility. The trace_info section has moved into such optional features, this is the first and only one for now. This is backward compatible with the .32 file version although it doesn't support the previous separate trace.info file. And finally it doesn't support the current interim development version. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Mike Galbraith Cc: Paul Mackerras Cc: Steven Rostedt LKML-Reference: <1255792354-11304-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed