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MDEV-7952 - clock_gettime() takes 0.24% in OLTP RO

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Initialize abs_timeout when it is about to be used. This saves one my_hrtime()
call on hot path (when we acquire MDL lock without waiting).

When filling I_S.PROCESSLIST use THD::start_utime/THD::utime_after_query instead
of THD::start_time. This allows us to save 2 clock_gettime() calls.

Overhead change:
__clock_gettime   0.13% -> 0.11% (122 -> 76 calls per OLTP RO transaction)
my_interval_timer 0.07% -> 0.06%
my_hrtime         0.04% -> 0.01%
This commit is contained in:
Sergey Vojtovich
2015-06-17 18:55:38 +04:00
parent 2bc6e29afe
commit 8f603bcbca
4 changed files with 18 additions and 16 deletions
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2
sql/sql_class.cc
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@@ -947,7 +947,7 @@ THD::THD(bool is_wsrep_applier)
// Must be reset to handle error with THD's created for init of mysqld
lex->current_select= 0;
user_time.val= start_time= start_time_sec_part= 0;
start_utime= prior_thr_create_utime= 0L;
start_utime= utime_after_query= prior_thr_create_utime= 0L;
utime_after_lock= 0L;
progress.arena= 0;
progress.report_to_client= 0;