From: Borislav Petkov <bp@alien8.de>
To: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
joro@8bytes.org, peterz@infradead.org, mingo@redhat.com
Subject: Re: [PATCH v8 3/9] perf/amd/iommu: Misc fix up perf_iommu_read
Date: Thu, 19 Jan 2017 11:01:48 +0100 [thread overview]
Message-ID: <20170119100148.vvmi7m2kpmtd6ylz@pd.tnic> (raw)
In-Reply-To: <1484551416-5440-4-git-send-email-Suravee.Suthikulpanit@amd.com>
> 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.
next prev parent reply other threads:[~2017-01-19 10:01 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-16 7:23 [PATCH v8 0/9] perf/amd/iommu: Enable multi-IOMMU support Suravee Suthikulpanit
2017-01-16 7:23 ` [PATCH v8 1/9] perf/amd/iommu: Declare pr_fmt and remove unnecessary pr_debug Suravee Suthikulpanit
2017-01-16 7:23 ` [PATCH v8 2/9] perf/amd/iommu: Clean up perf_iommu_enable_event Suravee Suthikulpanit
2017-01-18 18:20 ` Borislav Petkov
2017-01-16 7:23 ` [PATCH v8 3/9] perf/amd/iommu: Misc fix up perf_iommu_read Suravee Suthikulpanit
2017-01-19 10:01 ` Borislav Petkov [this message]
2017-01-23 12:33 ` Peter Zijlstra
2017-02-07 4:50 ` Suravee Suthikulpanit
2017-01-16 7:23 ` [PATCH v8 4/9] iommu/amd: Introduce amd_iommu_get_num_iommus() Suravee Suthikulpanit
2017-01-19 18:41 ` Borislav Petkov
2017-01-16 7:23 ` [PATCH v8 5/9] perf/amd/iommu: Modify functions to query max banks and counters Suravee Suthikulpanit
2017-01-22 19:53 ` Borislav Petkov
2017-01-16 7:23 ` [PATCH v8 6/9] perf/amd/iommu: Modify amd_iommu_pc_get_set_reg_val() API to allow specifying IOMMU index Suravee Suthikulpanit
2017-01-22 19:53 ` Borislav Petkov
2017-01-16 7:23 ` [PATCH v8 7/9] perf/amd/iommu: Check return value when set and get counter value Suravee Suthikulpanit
2017-01-22 19:53 ` Borislav Petkov
2017-01-23 12:31 ` Peter Zijlstra
2017-01-16 7:23 ` [PATCH v8 8/9] perf/amd/iommu: Fix sysfs perf attribute groups Suravee Suthikulpanit
2017-01-22 19:54 ` Borislav Petkov
2017-01-16 7:23 ` [PATCH v8 9/9] perf/amd/iommu: Enable support for multiple IOMMUs Suravee Suthikulpanit
2017-01-22 19:55 ` Borislav Petkov
2017-02-07 1:42 ` Suravee Suthikulpanit
2017-01-25 9:46 ` Peter Zijlstra
2017-01-25 9:55 ` Borislav Petkov
2017-02-07 1:58 ` Suravee Suthikulpanit
2017-02-07 1:57 ` Suravee Suthikulpanit
2017-02-14 12:31 ` Peter Zijlstra
2017-02-23 17:43 ` Suravee Suthikulpanit
2017-02-23 18:11 ` Peter Zijlstra
2017-02-23 18:20 ` Suravee Suthikulpanit
2017-01-17 15:36 ` [PATCH v8 0/9] perf/amd/iommu: Enable multi-IOMMU support Joerg Roedel
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