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| author |   Giovanni Gherdovich <ggherdovich@suse.cz> | 2020-05-31 20:24:53 +0200 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:10:02 +0200 |
| commit | f4291df103315a696f0b8c4f45ca8ae773c17441 (patch) | |
| tree | fa256aada4d4d8fdc892be4b1b15e993b3b503b6 /arch/x86/kernel/smpboot.c | |
| parent | x86, sched: Bail out of frequency invariance if turbo frequency is unknown (diff) | |
| download | linux-dev-f4291df103315a696f0b8c4f45ca8ae773c17441.tar.xz linux-dev-f4291df103315a696f0b8c4f45ca8ae773c17441.zip | |
x86, sched: Bail out of frequency invariance if turbo_freq/base_freq gives 0
Be defensive against the case where the processor reports a base_freq
larger than turbo_freq (the ratio would be zero).
Fixes: 1567c3e3467c ("x86, sched: Add support for frequency invariance")
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200531182453.15254-4-ggherdovich@suse.cz
Diffstat (limited to 'arch/x86/kernel/smpboot.c')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 20e1cea262e4..518ac6bf752e 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1977,6 +1977,7 @@ static bool core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq) static bool intel_set_max_freq_ratio(void) { u64 base_freq, turbo_freq; + u64 turbo_ratio; if (slv_set_max_freq_ratio(&base_freq, &turbo_freq)) goto out; @@ -2010,9 +2011,15 @@ out: return false; } - arch_turbo_freq_ratio = div_u64(turbo_freq * SCHED_CAPACITY_SCALE, - base_freq); + turbo_ratio = div_u64(turbo_freq * SCHED_CAPACITY_SCALE, base_freq); + if (!turbo_ratio) { + pr_debug("Non-zero turbo and base frequencies led to a 0 ratio.\n"); + return false; + } + + arch_turbo_freq_ratio = turbo_ratio; arch_set_max_freq_ratio(turbo_disabled()); + return true; } |