perf/x86: Improve debug output in check_hw_exists() (f285f92f) · Commits · 戴 / test

It might be of interest which perfctr msr failed. Signed-off-by:

Robert Richter <robert.richter@amd.com> [ added hunk to avoid GCC warn ] Signed-off-by:

arch/x86/kernel/cpu/perf_event.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -178,7 +178,7 @@ static void release_pmc_hardware(void) {}

		static bool check_hw_exists(void)
		{
		u64 val, val_new = 0;
		u64 val, val_new = ~0;
		int i, reg, ret = 0;

		/*
		@@ -211,8 +211,9 @@ static bool check_hw_exists(void)
		* that don't trap on the MSR access and always return 0s.
		*/
		val = 0xabcdUL;
		ret = wrmsrl_safe(x86_pmu_event_addr(0), val);
		ret \|= rdmsrl_safe(x86_pmu_event_addr(0), &val_new);
		reg = x86_pmu_event_addr(0);
		ret = wrmsrl_safe(reg, val);
		ret \|= rdmsrl_safe(reg, &val_new);
		if (ret \|\| val != val_new)
		goto msr_fail;

		@@ -229,6 +230,7 @@ bios_fail:

		msr_fail:
		printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n");
		printk(KERN_ERR "Failed to access perfctr msr (MSR %x is %Lx)\n", reg, val_new);

		return false;
		}