Re: [PATCH 3/3] domaincapsmoc.c: mock virHostCPUGetMicrocodeVersion()

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(a)gmail.com&gt; > --- > src/util/virhostcpu.h  | 3 ++- > tests/domaincapsmock.c | 6 ++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > Reviewed-by: Ján Tomko <jtomko(a)redhat.com&gt; Jano