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authorIan Rogers <irogers@google.com>2024-02-29 21:36:45 -0800
committerNamhyung Kim <namhyung@kernel.org>2024-03-03 22:52:13 -0800
commit7bfc84b23e750d746e5c6723270b9c7f92cfa88c (patch)
treef75a8dd94f2f6493d1359181da1b11f18cf395a2 /tools/perf
parent412a2ff473ac01b195eb38c0853ce065b524b2e2 (diff)
perf threads: Reduce table size from 256 to 8
The threads data structure is an array of hashmaps, previously rbtrees. The two levels allows for a fixed outer array where access is guarded by rw_semaphores. Commit 91e467bc568f ("perf machine: Use hashtable for machine threads") sized the outer table at 256 entries to avoid future scalability problems, however, this means the threads struct is sized at 30,720 bytes. As the hashmaps allow O(1) access for the common find/insert/remove operations, lower the number of entries to 8. This reduces the size overhead to 960 bytes. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Yang Jihong <yangjihong1@huawei.com> Cc: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240301053646.1449657-8-irogers@google.com
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/threads.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/util/threads.h b/tools/perf/util/threads.h
index d03bd91a7769..da68d2223f18 100644
--- a/tools/perf/util/threads.h
+++ b/tools/perf/util/threads.h
@@ -7,7 +7,7 @@
struct thread;
-#define THREADS__TABLE_BITS 8
+#define THREADS__TABLE_BITS 3
#define THREADS__TABLE_SIZE (1 << THREADS__TABLE_BITS)
struct threads_table_entry {