From 3ba4d2e1a8235d862657ded9f20b3170b477768b Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 6 Jan 2014 15:28:35 -0300 Subject: [PATCH] perf header: Pack 'struct perf_session_env' Initial struct: [acme@ssdandy linux]$ pahole -C perf_session_env ~/bin/perf struct perf_session_env { char * hostname; /* 0 8 */ char * os_release; /* 8 8 */ char * version; /* 16 8 */ char * arch; /* 24 8 */ int nr_cpus_online; /* 32 4 */ int nr_cpus_avail; /* 36 4 */ char * cpu_desc; /* 40 8 */ char * cpuid; /* 48 8 */ long long unsigned int total_mem; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ int nr_cmdline; /* 64 4 */ /* XXX 4 bytes hole, try to pack */ char * cmdline; /* 72 8 */ int nr_sibling_cores; /* 80 4 */ /* XXX 4 bytes hole, try to pack */ char * sibling_cores; /* 88 8 */ int nr_sibling_threads; /* 96 4 */ /* XXX 4 bytes hole, try to pack */ char * sibling_threads; /* 104 8 */ int nr_numa_nodes; /* 112 4 */ /* XXX 4 bytes hole, try to pack */ char * numa_nodes; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ int nr_pmu_mappings; /* 128 4 */ /* XXX 4 bytes hole, try to pack */ char * pmu_mappings; /* 136 8 */ int nr_groups; /* 144 4 */ /* size: 152, cachelines: 3, members: 20 */ /* sum members: 128, holes: 5, sum holes: 20 */ /* padding: 4 */ /* last cacheline: 24 bytes */ }; [acme@ssdandy linux]$ [acme@ssdandy linux]$ pahole -C perf_session_env --reorganize --show_reorg_steps ~/bin/perf | grep ^/ | grep -v Final /* Moving 'nr_sibling_cores' from after 'cmdline' to after 'nr_cmdline' */ /* Moving 'nr_numa_nodes' from after 'sibling_threads' to after 'nr_sibling_threads' */ /* Moving 'nr_groups' from after 'pmu_mappings' to after 'nr_pmu_mappings' */ [acme@ssdandy linux]$ Final struct stats: [acme@ssdandy linux]$ pahole -C perf_session_env --reorganize --show_reorg_steps ~/bin/perf | tail -4 /* --- cacheline 2 boundary (128 bytes) --- */ /* size: 128, cachelines: 2, members: 20 */ }; /* saved 24 bytes and 1 cacheline! */ [acme@ssdandy linux]$ Cc: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-3d9tshamloinzxcqeb7mtd1n@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 307c9ae..a2d047b 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -77,16 +77,16 @@ struct perf_session_env { unsigned long long total_mem; int nr_cmdline; - char *cmdline; int nr_sibling_cores; - char *sibling_cores; int nr_sibling_threads; - char *sibling_threads; int nr_numa_nodes; - char *numa_nodes; int nr_pmu_mappings; - char *pmu_mappings; int nr_groups; + char *cmdline; + char *sibling_cores; + char *sibling_threads; + char *numa_nodes; + char *pmu_mappings; }; struct perf_header { -- 2.7.4