linux.git/kernel/irq/timings.c, branch v5.13

irq: Fix typos in comments

2021-03-22T03:23:14+00:00

Fix ~36 single-word typos in the IRQ, irqchip and irqdomain code comments.

Signed-off-by: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Marc Zyngier 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

genirq: Fix typos and misspellings in comments

2021-03-16T14:08:29+00:00

No functional change.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210316100205.23492-1-krzysztof.kozlowski@canonical.com

kernel/: fix repeated words in comments

2020-10-16T18:11:19+00:00

Fix multiple occurrences of duplicated words in kernel/.

Fix one typo/spello on the same line as a duplicate word.  Change one
instance of "the the" to "that the".  Otherwise just drop one of the
repeated words.

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org
Signed-off-by: Linus Torvalds

genirq/timings: Add selftest for next event computation

2019-06-12T08:47:05+00:00

The circular buffers are now validated with selftests. The next interrupt
index algorithm which is the hardest part to validate needs extra coverage.

Add a selftest which uses the intervals stored in the arrays and insert all
the values except the last one. The next event computation must return the
same value as the last element which was not inserted.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-9-daniel.lezcano@linaro.org

genirq/timings: Add selftest for irqs circular buffer

2019-06-12T08:47:05+00:00

After testing the per cpu interrupt circular event, make sure the per
interrupt circular buffer usage is correct.

Add tests to validate the interrupt circular buffer.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-8-daniel.lezcano@linaro.org

genirq/timings: Add selftest for circular array

2019-06-12T08:47:04+00:00

Due to the complexity of the code and the difficulty to debug it, add some
selftests to the framework in order to spot issues or regression at boot
time when the runtime testing is enabled for this subsystem.

This tests the circular buffer at the limits and validates:
 - the encoding / decoding of the values
 - the macro to browse the irq timings circular buffer
 - the function to push data in the circular buffer

Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-7-daniel.lezcano@linaro.org

genirq/timings: Encapsulate storing function

2019-06-12T08:47:04+00:00

For the next patches providing the selftest, it is required to insert
interval values directly in the buffer in order to check the correctness of
the code. Encapsulate the code doing that in a always inline function in
order to reuse it in the test code.

No functional changes.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-6-daniel.lezcano@linaro.org

genirq/timings: Optimize the period detection speed

2019-06-12T08:47:03+00:00

With a minimal period and if there is a period which is a multiple of it
but lesser than the max period then it will be detected before and the
minimal period will be never reached.

 1 2 1 2 1 2 1 2 1 2 1 2
 <-----> <-----> <----->
 <-> <-> <-> <-> <-> <->

In that case, the minimum period is 2 and the maximum period is 5. That
means all repeating pattern of 2 will be detected as repeating pattern of
4, it is pointless to go up to 2 when searching for the period as it will
always fail.

Remove one loop iteration by increasing the minimal period to 3.

Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-4-daniel.lezcano@linaro.org

genirq/timings: Fix timings buffer inspection

2019-06-12T08:47:03+00:00

It appears the index beginning computation is not correct, the current
code does:

     i = (irqts->count & IRQ_TIMINGS_MASK) - 1

If irqts->count is equal to zero, we end up with an index equal to -1,
but that does not happen because the function checks against zero
before and returns in such case.

However, if irqts->count is a multiple of IRQ_TIMINGS_SIZE, the
resulting & bit op will be zero and leads also to a -1 index.

Re-introduce the iteration loop belonging to the previous variance
code which was correct.

Fixes: bbba0e7c5cda "genirq/timings: Add array suffix computation code"
Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-3-daniel.lezcano@linaro.org

genirq/timings: Fix next event index function

2019-06-12T08:47:03+00:00

The current code is luckily working with most of the interval samples
testing but actually it fails to correctly detect pattern repetition
breaking at the end of the buffer.

Narrowing down the bug has been a real pain because of the pointers,
so the routine is rewrittne by using indexes instead.

Fixes: bbba0e7c5cda "genirq/timings: Add array suffix computation code"
Signed-off-by: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-2-daniel.lezcano@linaro.org