s/capsmoc.c/capsmock/ On a Monday in 2020, Daniel Henrique Barboza wrote:
Previous patch handled the runtime case where a non-x86 host is fetching /proc/cpuinfo data for a microcode info that we know it doesn't exist. This change alone speeded everything by a bit for non-x86, but there is at least one major culprit left. qemuxml2argvtest does several arch-specific tests, and a good chunk of them are x86 exclusive. This means that 'hostArch' will be seen as x86 for these tests, even when running in non-x86 hosts. In a Power 9 server with 128 CPUs, qemuxmlargvtest
*qemuxml2argvtest
takes 298 seconds to complete in average, and 'perf record' indicates that 95% of the time is spent in virHostCPUGetMicrocodeVersion().
No surprise, we call it 23448 times.
This patch mocks virHostCPUGetMicrocodeVersion() to always return 0 in the tests, avoiding /proc/cpuinfo reads. This will make all tests behave arch-agnostic, and the microcode value being 0 has no impact on any existing test. This is a CI speed across the board for all archs, including x86, given that we're not reading /proc/cpuinfo in the tests. For a Thinkpad T480 laptop with 8 Intel i7 CPUs, qemuxml2argvtest went from 15.50 sec to 12.50 seconds. The performance gain is even more noticeable for huge servers with lots of CPUs. For the Power 9 server mentioned above, this patch speeds qemuxml2argvtest to 9 seconds, down from 298 sec.
I assume the speedup for Power is measured for the whole series, not just for this patch.
Signed-off-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx> --- src/util/virhostcpu.h | 3 ++- tests/domaincapsmock.c | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-)
Reviewed-by: Ján Tomko <jtomko@xxxxxxxxxx> Jano
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