On 08/11/2015 10:49 AM, Eric Dumazet wrote: > On Tue, 2015-08-11 at 14:38 +0000, Jason Baron wrote: >> From: Jason Baron <jba...@akamai.com> > >> In my testing, this brought a single threaad's cpu usage down from 100% to >> ~1% >> while maintaining the same level of throughput. >> > > Hi Jason. Could you give more details on this test ? > > How many flows are competing ? > >
Yes, so the test case I'm using to test against is somewhat contrived. In that I am simply allocating around 40,000 sockets that are idle to create a 'permanent' memory pressure in the background. Then, I have just 1 flow that sets SO_SNDBUF, which results in the: poll(), write() loop. That said, we encountered this issue initially where we had 10,000+ flows and whenever the system would get into memory pressure, we would see all the cpus spin at 100%. So the testcase I wrote, was just a simplistic version for testing. But I am going to try and test against the more realistic workload where this issue was initially observed. Thanks, -Jason -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
