kernel.git/arch/parisc/kernel/time.c, branch linux-4.13.y

parisc: Fix detection of nonsynchronous cr16 cycle counters

2017-10-27T08:39:09Z

commit 8642b31ba9eef8a01845146a26682d4869e62513 upstream. For CPUs which have an unknown or invalid CPU location (physical location) assume that their cycle counters aren't syncronized across CPUs. Signed-off-by: Helge Deller Fixes: c8c3735997a3 ("parisc: Enhance detection of synchronous cr16 clocksources") Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Enhance detection of synchronous cr16 clocksources

2017-05-10T15:46:14Z

The cr16 clocks of the physical PARISC CPUs are usually nonsynchronous. Nevertheless, it seems that each CPU socket (which holds two cores) of PA8800 and PA8900 CPUs (e.g. in a C8000 workstation) is fed by the same clock source, which makes the cr16 clocks of each CPU socket syncronous. Let's try to detect such situations and mark the cr16 clocksource stable on single-socket and single-core machines. Signed-off-by: Helge Deller

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:27Z

We are going to split out of , which will have to be picked up from other headers and .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

parisc: Mark cr16 clocksource unstable on SMP systems

2016-12-29T20:51:30Z

The cr16 interval timer of each CPU is not syncronized to other cr16 timers in other CPUs in a SMP system. So, delay the registration of the cr16 clocksource until all CPUs have been detected and then - if we are on a SMP machine - mark the cr16 clocksource as unstable and lower it's rating before registering it at the clocksource framework. This patch fixes the stalled CPU warnings which we have seen since introduction of the cr16 clocksource. Signed-off-by: Helge Deller Cc: # v4.8+

clocksource: Use a plain u64 instead of cycle_t

2016-12-25T10:04:12Z

There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: John Stultz

Replace with globally

2016-12-24T19:46:01Z

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

parisc: Optimize timer interrupt function

2016-12-20T20:39:40Z

Restructure the timer interrupt function to better cope with missed timer irqs. Optimize the calculation when the next interrupt should happen and skip irqs if they would happen too shortly after exit of the irq function. The update_process_times() call is done anyway at every timer irq, so we can safely drop the prof_counter and prof_multiplier variables from the per_cpu structure. Signed-off-by: Helge Deller

parisc: Switch to generic sched_clock implementation

2016-11-25T11:31:58Z

Drop the open-coded sched_clock() function and replace it by the provided GENERIC_SCHED_CLOCK implementation. We have seen quite some hung tasks in the past, which seem to be fixed by this patch. Signed-off-by: Helge Deller Cc: # v4.7+ Signed-off-by: Helge Deller

parisc: Fix self-detected CPU stall warnings on Mako machines

2016-09-25T19:27:01Z

The config option HAVE_UNSTABLE_SCHED_CLOCK is set automatically when compiling for SMP. There is no need to clear the stable-clock flag via clear_sched_clock_stable() when starting secondary CPUs, and even worse, clearing it triggers wrong self-detected CPU stall warnings on 64bit Mako machines. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # 4.7+

parisc: Fix automatic selection of cr16 clocksource

2016-08-20T11:33:51Z

Commit 54b66800907 (parisc: Add native high-resolution sched_clock() implementation) added support to use the CPU-internal cr16 counters as reliable clocksource with the help of HAVE_UNSTABLE_SCHED_CLOCK. Sadly the commit missed to remove the hack which prevented cr16 to become the default clocksource even on SMP systems. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # 4.7+