From ee04f0746f5c649bba7ec2a2075c1f0a1d121422 Mon Sep 17 00:00:00 2001 From: Stefan Fritsch Date: Sun, 13 Jun 2010 12:44:51 +0000 Subject: [PATCH] Add comment that using cur_unique_id.counter from all threads is bad for performance on SMP systems. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@954213 13f79535-47bb-0310-9956-ffa450edef68 --- modules/metadata/mod_unique_id.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/modules/metadata/mod_unique_id.c b/modules/metadata/mod_unique_id.c index f828fb348c..fe4252b48e 100644 --- a/modules/metadata/mod_unique_id.c +++ b/modules/metadata/mod_unique_id.c @@ -118,6 +118,12 @@ typedef struct { static unsigned global_in_addr; +/* + * XXX: We should have a per-thread counter and not use cur_unique_id.counter + * XXX: in all threads, because this is bad for performance on multi-processor + * XXX: systems: Writing to the same address from several CPUs causes cache + * XXX: thrashing. + */ static unique_id_rec cur_unique_id; /* -- 2.50.1