From ec532e2c5c0b25fb7ab09383fe5a274583a90def Mon Sep 17 00:00:00 2001 From: Qi Wang Date: Thu, 2 Feb 2017 17:02:05 -0800 Subject: Implement per-CPU arena. The new feature, opt.percpu_arena, determines thread-arena association dynamically based CPU id. Three modes are supported: "percpu", "phycpu" and disabled. "percpu" uses the current core id (with help from sched_getcpu()) directly as the arena index, while "phycpu" will assign threads on the same physical CPU to the same arena. In other words, "percpu" means # of arenas == # of CPUs, while "phycpu" has # of arenas == 1/2 * (# of CPUs). Note that no runtime check on whether hyper threading is enabled is added yet. When enabled, threads will be migrated between arenas when a CPU change is detected. In the current design, to reduce overhead from reading CPU id, each arena tracks the thread accessed most recently. When a new thread comes in, we will read CPU id and update arena if necessary. --- src/stats.c | 1 + 1 file changed, 1 insertion(+) (limited to 'src/stats.c') diff --git a/src/stats.c b/src/stats.c index ae360e1b..776fb862 100644 --- a/src/stats.c +++ b/src/stats.c @@ -621,6 +621,7 @@ stats_general_print(void (*write_cb)(void *, const char *), void *cbopaque, OPT_WRITE_BOOL(abort, ",") OPT_WRITE_CHAR_P(dss, ",") OPT_WRITE_UNSIGNED(narenas, ",") + OPT_WRITE_CHAR_P(percpu_arena, ",") OPT_WRITE_SSIZE_T_MUTABLE(decay_time, arenas.decay_time, ",") OPT_WRITE_CHAR_P(junk, ",") OPT_WRITE_BOOL(zero, ",") -- cgit v1.2.3