Comment 0 for bug 1516557

On the idle fresh env several services consume CPU, in average 1,5% per each. The issue is introduced in 8.0 and not observable in 7.0. Affected services: nova-api, cinder-api, glance-api, swift-api.

strace shows the following loop:
select(0, NULL, NULL, NULL, {0, 9714}) = 0 (Timeout)
gettimeofday({1447668681, 29496}, NULL) = 0
wait4(0, 0x7ffe4ca6d890, WNOHANG, NULL) = 0
gettimeofday({1447668681, 29639}, NULL) = 0
gettimeofday({1447668681, 29711}, NULL) = 0

On MOS 7 the loop was different from project to project and didn't result in visible CPU consumption. In all cases it didn't contain calls to gettimeofday.