From 4cf40131a5cf4918e83b3756e58a1fc9e984f8ef Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Sun, 27 Dec 2009 21:37:06 -0200 Subject: perf record: Introduce a symtab cache MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now a cache will be created in a ~/.debug debuginfo like hierarchy, so that at the end of a 'perf record' session all the binaries (with build-ids) involved get collected and indexed by their build-ids, so that perf report can find them. This is interesting when developing software where you want to do a 'perf diff' with the previous build and opens avenues for lots more interesting tools, like a 'perf diff --graph' that takes more than two binaries into account. Tunables for collecting just the symtabs can be added if one doesn't want to have the full binary, but having the full binary allows things like 'perf rerecord' or other tools that can re-run the tests by having access to the exact binary in some perf.data file, so it may well be interesting to keep the full binary there. Space consumption is minimised by trying to use hard links, a 'perf cache' tool to manage the space used, a la ccache is required to purge older entries. With this in place it will be possible also to introduce new commands, 'perf archive' and 'perf restore' (or some more suitable and future proof names) to create a cpio/tar file with the perf data and the files in the cache that _had_ perf hits of interest. There are more aspects to polish, like finding the right vmlinux file to cache, etc, but this is enough for a first step. Signed-off-by: Arnaldo Carvalho de Melo Cc: Frédéric Weisbecker Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <1261957026-15580-10-git-send-email-acme@infradead.org> Signed-off-by: Ingo Molnar --- tools/perf/util/symbol.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/perf/util/symbol.h') diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 9eabd60f819..f27e158943e 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -8,6 +8,8 @@ #include #include "event.h" +#define DEBUG_CACHE_DIR ".debug" + #ifdef HAVE_CPLUS_DEMANGLE extern char *cplus_demangle(const char *, int); -- cgit v1.2.3-70-g09d2