you are missing the reason. read the paper. brucee
On 22 September 2013 12:55, erik quanstrom <quans...@quanstro.net> wrote: > when i measure chan send performance with the attached program with > the semaphore locks that have been made the default for sources and > with the old locks, the old locks surprisingly outperform the new ones > by a large margin. > > the test is let O be the number of buffers in the channel, and M be > the number of sending procs, then cycles is the number of machine > cycles required to send 1<<21 messages per proc, and receive them > on a single listener. > > on my machine, i get the following raw numbers (averaged over a few tries): > > new 1.84e9 cycles O=10 M=1 > old 1.10e9 > > new 4.61e9 O=0 M=1 > old 4.38e9 > > new 1.55e10 O=10 M=8 > old 2.74e10 > > new 3.64e10 O=0 M=8 > old 5.14e10 > > am i doing something fundamental wrong, or are the new locks substantially > slower than the old ones? > > - erik
