Re: [PATCH v2 36/40] tracing: Remove lookups from tracing_map hitcount
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: 2017-09-12 02:16:17
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Hi Tom, On Tue, 5 Sep 2017 16:57:48 -0500 Tom Zanussi [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Lookups inflate the hitcount, making it essentially useless. Only inserts and updates should really affect the hitcount anyway, so explicitly filter lookups out. Signed-off-by: Tom Zanussi <redacted> --- kernel/trace/tracing_map.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index a4e5a56..f8e2338 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c@@ -538,7 +538,8 @@ static inline bool keys_match(void *key, void *test_key, unsigned key_size) if (test_key && test_key == key_hash) { if (entry->val && keys_match(key, entry->val->key, map->key_size)) { - atomic64_inc(&map->hits); + if (!lookup_only) + atomic64_inc(&map->hits);
Is this a kind of bugfix for current code? If so, such patch can be posted in separate series. Thank you,
return entry->val;
} else if (unlikely(!entry->val)) {
/*
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1.9.3-- Masami Hiramatsu [off-list ref]