From 46d88d8dba56c1e3e11cc5adb835d4ce9d627e94 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Mon, 24 Aug 2020 10:27:54 -0300 Subject: [PATCH] domaincapsmock: mock virHostCPUGetMicrocodeVersion() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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, qemuxml2argvtest takes 298 seconds to complete in average, and 'perf record' indicates that 95% of the time is spent in virHostCPUGetMicrocodeVersion(). 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. Signed-off-by: Daniel Henrique Barboza Reviewed-by: Ján Tomko Signed-off-by: Ján Tomko --- src/util/virhostcpu.h | 3 ++- tests/domaincapsmock.c | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/src/util/virhostcpu.h b/src/util/virhostcpu.h index 11cbcd72a3..6148f9e66f 100644 --- a/src/util/virhostcpu.h +++ b/src/util/virhostcpu.h @@ -75,7 +75,8 @@ virBitmapPtr virHostCPUGetSiblingsList(unsigned int cpu); int virHostCPUGetOnline(unsigned int cpu, bool *online); -unsigned int virHostCPUGetMicrocodeVersion(virArch hostArch); +unsigned int +virHostCPUGetMicrocodeVersion(virArch hostArch) G_GNUC_NO_INLINE; int virHostCPUGetMSR(unsigned long index, uint64_t *msr); diff --git a/tests/domaincapsmock.c b/tests/domaincapsmock.c index 90e17c19f0..d81a898dc0 100644 --- a/tests/domaincapsmock.c +++ b/tests/domaincapsmock.c @@ -34,3 +34,9 @@ virHostCPUGetKVMMaxVCPUs(void) { return INT_MAX; } + +unsigned int +virHostCPUGetMicrocodeVersion(virArch hostArch G_GNUC_UNUSED) +{ + return 0; +}