From c2c184dc957551e4232391b657df33aec73ef8fb Mon Sep 17 00:00:00 2001 From: rpj Date: Sun, 1 May 2005 08:29:54 +0000 Subject: '' --- tests/README.BENCHTESTS | 37 +++++++------------------------------ 1 file changed, 7 insertions(+), 30 deletions(-) (limited to 'tests/README.BENCHTESTS') diff --git a/tests/README.BENCHTESTS b/tests/README.BENCHTESTS index e02cb3e..448570c 100644 --- a/tests/README.BENCHTESTS +++ b/tests/README.BENCHTESTS @@ -2,7 +2,7 @@ ------------ Benchmarking ------------ -There is a new but growing set a benchmarking programs in the +There is a set a benchmarking programs in the "tests" directory. These should be runnable using the following command-lines corresponding to each of the possible library builds: @@ -62,36 +62,13 @@ irrespective of the Windows variant, and should therefore have consistent performance. +Semaphore benchtests +-------------------- + +benchtest5 - Timing for various uncontended cases. + + In all benchtests, the operation is repeated a large number of times and an average is calculated. Loop overhead is measured and subtracted from all test times. -Comment on the results ----------------------- -The gain in performance for Win9x systems is enormous - up to -40 times faster for unlocked mutexes (2 times faster for locked -mutexes). - -Pthread_mutex_trylock also appears to be faster for locked mutexes. - -The price for the new consistency between WinNT and Win9x is -slower performance (up to twice as long) across a lock/unlock -sequence. It is difficult to get a good split timing for lock -and unlock operations, but by code inspection, it is the unlock -operation that is slowing the pair down in comparison with the -old-style CS mutexes, even for the fast PTHREAD_MUTEX_NORMAL mutex -type with no other waiting threads. However, comparitive -performance for operations on already locked mutexes is very close. - -When this is translated to real-world applications, the overall -camparitive performance should be almost identical on NT class -systems. That is, applications with heavy mutex contention should -have almost equal performance, while applications with only light -mutex contention should also have almost equal performance because -the most critical operation in this case is the lock operation. - -Overall, the newer pthreads-win32 mutex routines are only slower -(on NT class systems) where and when it is least critical. - -Thanks go to Thomas Pfaff for the current implementation of mutex -routines. -- cgit v1.2.3