Hello! On Thu, Jun 02, 2016 at 08:48:19PM +0800, Sepherosa Ziehau wrote:
> On DragonflyBSD only clock_gettime(*_FAST) avoids system call and time > counter read cost (kinda like Linux VDSO). This gives some > improvement for performance and reduces latency. At least FreeBSD also has clock_gettime(*_FAST), from where it was taken to DragonFly BSD. And Linux 2.6.32+ has clock_gettime(*_COARSE). We do have plans to use monotonic versions, see https://trac.nginx.org/nginx/ticket/189. > My testing setup consists two clients and one nginx (recent head code) > server, two clients connected to the nginx server through two 10Ge > (82599). 15K concurrent connections from each client; client runs a > modified version of wrk and each connection only carries one request > for an 1KB file. > > Performance goes from 183Kreqs/s to 184Kreqs/s (admittedly pretty > minor). Average latency reduces 2ms (98ms -> 96ms). Latency stdev > reduces 6ms (198ms -> 192ms). This doesn't look statistically significant. Have you tried something like ministat(1) to test the results? Note that nginx only uses gettimeofday() once per event loop iteration, so I wouldn't expect it to make measureable difference. [...] -- Maxim Dounin http://nginx.org/ _______________________________________________ nginx-devel mailing list [email protected] http://mailman.nginx.org/mailman/listinfo/nginx-devel
