Messages in this thread | | | Date | Thu, 19 Jan 2017 11:01:48 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v8 3/9] perf/amd/iommu: Misc fix up perf_iommu_read |
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> Subject: Re: [PATCH v8 3/9] perf/amd/iommu: Misc fix up perf_iommu_read
Please be a bit more thorough when writing your commit messages. What is a "misc fix up"? Perhaps it is ok for a quick'n'dirty local patch but not when it is for upstream.
Also, function names end with "()" to denote they're functions.
On Mon, Jan 16, 2017 at 01:23:30AM -0600, Suravee Suthikulpanit wrote: > * Fix overflow handling since u64 delta would lose the MSB sign bit. > * Remove unnecessary local64_cmpxchg(). > * Coding style and make use of GENMASK_ULL macro.
That last one doesn't read like a sentence.
> Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Borislav Petkov <bp@alien8.de> > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> > --- > arch/x86/events/amd/iommu.c | 23 ++++++++++++----------- > 1 file changed, 12 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c > index 1aa25d8..3f1c18a 100644 > --- a/arch/x86/events/amd/iommu.c > +++ b/arch/x86/events/amd/iommu.c > @@ -320,9 +320,8 @@ static void perf_iommu_start(struct perf_event *event, int flags) > > static void perf_iommu_read(struct perf_event *event) > { > - u64 count = 0ULL; > - u64 prev_raw_count = 0ULL; > - u64 delta = 0ULL; > + u64 count, prev; > + s64 delta; > struct hw_perf_event *hwc = &event->hw; > > amd_iommu_pc_get_set_reg_val(_GET_DEVID(event), > @@ -330,18 +329,20 @@ static void perf_iommu_read(struct perf_event *event) > IOMMU_PC_COUNTER_REG, &count, false); > > /* IOMMU pc counter register is only 48 bits */ > - count &= 0xFFFFFFFFFFFFULL; > + count &= GENMASK_ULL(48, 0);
GENMASK_ULL(48, 0) gives 0x1ffffffffffff, however. Which is 49 bits.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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