postgres.git / summary / log / commit / refs

commit    6ec1ff852f0ab13973979df311b0ac2be9e207b1
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Apr 18 17:33:07 2016 +0000
First released in: 9.6.0, 9.2.17, 9.3.13, 9.4.8, 9.5.3

    Further reduce the number of semaphores used under --disable-spinlocks.
    
    Per discussion, there doesn't seem to be much value in having
    NUM_SPINLOCK_SEMAPHORES set to 1024: under any scenario where you are
    running more than a few backends concurrently, you really had better have a
    real spinlock implementation if you want tolerable performance.  And 1024
    semaphores is a sizable fraction of the system-wide SysV semaphore limit
    on many platforms.  Therefore, reduce this setting's default value to 128
    to make it less likely to cause out-of-semaphores problems.


 src/include/pg_config_manual.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index 74d7ba2010a..4aefaf7fec6 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -62,7 +62,7 @@
  * may improve performance, but supplying a real spinlock implementation is
  * probably far better.
  */
-#define	NUM_SPINLOCK_SEMAPHORES		1024
+#define	NUM_SPINLOCK_SEMAPHORES		128
 
 /*
  * Define this if you want to allow the lo_import and lo_export SQL


[parent: 35166fd7614e]