From dbc984c961667b1ce48a0337b5bcd3b8c9cb2098 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 18 Nov 2019 16:26:29 -0300 Subject: perf map: Use bitmap for booleans The map->priv and map->erange_warned are seldom used, the first only in tests/vmlinux-kallsyms.c, the later only when hist_entry__inc_addr_samples() returns -ERANGE in 'perf top', which are really rare occasions, so make them a bool bitfield. This will open up space for other members on the first cacheline. $ pahole -C map ~/bin/perf struct map { union { struct rb_node rb_node __attribute__((__aligned__(8))); /* 0 24 */ struct list_head node; /* 0 16 */ } __attribute__((__aligned__(8))); /* 0 24 */ u64 start; /* 24 8 */ u64 end; /* 32 8 */ _Bool erange_warned:1; /* 40: 0 1 */ _Bool priv:1; /* 40: 1 1 */ /* XXX 6 bits hole, try to pack */ /* XXX 3 bytes hole, try to pack */ u32 prot; /* 44 4 */ u32 flags; /* 48 4 */ /* XXX 4 bytes hole, try to pack */ u64 pgoff; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 reloc; /* 64 8 */ u32 maj; /* 72 4 */ u32 min; /* 76 4 */ u64 ino; /* 80 8 */ u64 ino_generation; /* 88 8 */ u64 (*map_ip)(struct map *, u64); /* 96 8 */ u64 (*unmap_ip)(struct map *, u64); /* 104 8 */ struct dso * dso; /* 112 8 */ refcount_t refcnt; /* 120 4 */ /* size: 128, cachelines: 2, members: 17 */ /* sum members: 116, holes: 2, sum holes: 7 */ /* sum bitfield members: 2 bits, bit holes: 1, sum bit holes: 6 bits */ /* padding: 4 */ /* forced alignments: 1 */ } __attribute__((__aligned__(8))); $ Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-g5545pcq4ff0wr17tfb1piqt@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/map.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index a31e80991189..e2466aa5bb41 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -25,8 +25,8 @@ struct map { }; u64 start; u64 end; - bool erange_warned; - u32 priv; + bool erange_warned:1; + bool priv:1; u32 prot; u32 flags; u64 pgoff; -- cgit v1.2.3-59-g8ed1b