Date: Wed, 20 Feb 2019 20:55:15 +0300 From: Slawa Olhovchenkov <slw@zxy.spb.ru> To: Farhan Khan <farhan@farhan.codes> Cc: freebsd-hackers@freebsd.org Subject: Re: Optimize execution of processes by CPU core Message-ID: <20190220175515.GA2178@zxy.spb.ru> In-Reply-To: <2fcd9aee092730e11880c3ae88de4898@farhan.codes> References: <2fcd9aee092730e11880c3ae88de4898@farhan.codes>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 20, 2019 at 05:35:21PM +0000, Farhan Khan via freebsd-hackers wrote: > Hi all, > > I am trying to optimize the execution of a CPU-intensive workload where I am running multiple instances of a program. The moment the program ends (expected behavior), the calling shell script verifies the results and if its good it reruns the program. The machines I am running this on have 8 cores, but ps reports that some of the processes frequently run on the same CPU, so I suspect I am not getting optimized performance. If possible, and if most efficient, I would like to run each process on its own CPU core. > > Are there any best practices on how to run something like this? I understand cpuset can perform some functionality around this, but I do not understand the tooling (The man page speaks of a CPU set?) Would I do something like "cpuset -c -l 0 program arg1 arg2 arg3" in one script, and then "cpuset -c -l 1 program arg1 arg2 arg3" in the next up to 7? just "cpuset -l 0 program arg1 arg2 arg3" and etc. (w/o "-c") > Obviously it would be best to re-write the program to handle multiple threads in in an optimized way, but that would take more time than the optimization would likely save. for every thread: char name[128]; cpuset_t mask; pthread_attr_t attr; pthread_attr_init(&attr); CPU_ZERO(&mask); CPU_SET(cpu, &mask); pthread_attr_setaffinity_np(&attr, sizeof(mask), &mask); pthread_create(&tid[n], &attr, worker_thread, (void *)args); snprintf(name, 128, "worker CPU#%d", cpu); pthread_set_name_np(tid[n], name);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20190220175515.GA2178>