Messages in this thread Patch in this message | | | Date | Tue, 24 Oct 2023 15:23:13 -0700 | Subject | [PATCH v3 10/50] perf callchain: Minor layout changes to callchain_list | From | Ian Rogers <> |
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Avoid 6 byte hole for padding. Place more frequently used fields first in an attempt to use just 1 cacheline in the common case.
Before: ``` struct callchain_list { u64 ip; /* 0 8 */ struct map_symbol ms; /* 8 24 */ struct { _Bool unfolded; /* 32 1 */ _Bool has_children; /* 33 1 */ }; /* 32 2 */
/* XXX 6 bytes hole, try to pack */
u64 branch_count; /* 40 8 */ u64 from_count; /* 48 8 */ u64 predicted_count; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 abort_count; /* 64 8 */ u64 cycles_count; /* 72 8 */ u64 iter_count; /* 80 8 */ u64 iter_cycles; /* 88 8 */ struct branch_type_stat * brtype_stat; /* 96 8 */ const char * srcline; /* 104 8 */ struct list_head list; /* 112 16 */
/* size: 128, cachelines: 2, members: 13 */ /* sum members: 122, holes: 1, sum holes: 6 */ }; ```
After: ``` struct callchain_list { struct list_head list; /* 0 16 */ u64 ip; /* 16 8 */ struct map_symbol ms; /* 24 24 */ const char * srcline; /* 48 8 */ u64 branch_count; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 from_count; /* 64 8 */ u64 cycles_count; /* 72 8 */ u64 iter_count; /* 80 8 */ u64 iter_cycles; /* 88 8 */ struct branch_type_stat * brtype_stat; /* 96 8 */ u64 predicted_count; /* 104 8 */ u64 abort_count; /* 112 8 */ struct { _Bool unfolded; /* 120 1 */ _Bool has_children; /* 121 1 */ }; /* 120 2 */
/* size: 128, cachelines: 2, members: 13 */ /* padding: 6 */ }; ```
Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/util/callchain.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h index 86e8a9e81456..d5c66345ae31 100644 --- a/tools/perf/util/callchain.h +++ b/tools/perf/util/callchain.h @@ -116,22 +116,22 @@ extern struct callchain_param callchain_param; extern struct callchain_param callchain_param_default; struct callchain_list { + struct list_head list; u64 ip; struct map_symbol ms; - struct /* for TUI */ { - bool unfolded; - bool has_children; - }; + const char *srcline; u64 branch_count; u64 from_count; - u64 predicted_count; - u64 abort_count; u64 cycles_count; u64 iter_count; u64 iter_cycles; struct branch_type_stat *brtype_stat; - const char *srcline; - struct list_head list; + u64 predicted_count; + u64 abort_count; + struct /* for TUI */ { + bool unfolded; + bool has_children; + }; }; /* -- 2.42.0.758.gaed0368e0e-goog
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