Revision 2548d546d40c0014efdde88a53bf7896e917dcce authored by Peter Zijlstra on 21 April 2016, 16:03:15 UTC, committed by Ingo Molnar on 28 April 2016, 08:28:55 UTC
Chris Metcalf reported a that sched_can_stop_tick() sometimes fails to re-enable the tick. His observed problem is that rq->cfs.nr_running can be 1 even though there are multiple runnable CFS tasks. This happens in the cgroup case, in which case cfs.nr_running is the number of runnable entities for that level. If there is a single runnable cgroup (which can have an arbitrary number of runnable child entries itself) rq->cfs.nr_running will be 1. However, looking at that function I think there's more problems with it. It seems to assume that if there's FIFO tasks, those will run. This is incorrect. The FIFO task can have a lower prio than an RR task, in which case the RR task will run. So the whole fifo_nr_running test seems misplaced, it should go after the rr_nr_running tests. That is, only if !rr_nr_running, can we use fifo_nr_running like this. Reported-by: Chris Metcalf <cmetcalf@mellanox.com> Tested-by: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Wanpeng Li <kernellwp@gmail.com> Fixes: 76d92ac305f2 ("sched: Migrate sched to use new tick dependency mask model") Link: http://lkml.kernel.org/r/20160421160315.GK24771@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kconfig | -rw-r--r-- | 22.0 KB |
Makefile | -rw-r--r-- | 4.1 KB |
spi-adi-v3.c | -rw-r--r-- | 24.9 KB |
spi-altera.c | -rw-r--r-- | 7.1 KB |
spi-ath79.c | -rw-r--r-- | 7.3 KB |
spi-atmel.c | -rw-r--r-- | 45.0 KB |
spi-au1550.c | -rw-r--r-- | 25.7 KB |
spi-axi-spi-engine.c | -rw-r--r-- | 14.9 KB |
spi-bcm2835.c | -rw-r--r-- | 23.0 KB |
spi-bcm2835aux.c | -rw-r--r-- | 14.7 KB |
spi-bcm53xx.c | -rw-r--r-- | 6.9 KB |
spi-bcm53xx.h | -rw-r--r-- | 2.6 KB |
spi-bcm63xx-hsspi.c | -rw-r--r-- | 12.5 KB |
spi-bcm63xx.c | -rw-r--r-- | 16.1 KB |
spi-bfin-sport.c | -rw-r--r-- | 22.7 KB |
spi-bfin5xx.c | -rw-r--r-- | 39.7 KB |
spi-bitbang-txrx.h | -rw-r--r-- | 3.3 KB |
spi-bitbang.c | -rw-r--r-- | 10.5 KB |
spi-butterfly.c | -rw-r--r-- | 8.3 KB |
spi-cadence.c | -rw-r--r-- | 20.2 KB |
spi-clps711x.c | -rw-r--r-- | 5.2 KB |
spi-coldfire-qspi.c | -rw-r--r-- | 13.1 KB |
spi-davinci.c | -rw-r--r-- | 29.0 KB |
spi-dln2.c | -rw-r--r-- | 20.7 KB |
spi-dw-mid.c | -rw-r--r-- | 7.9 KB |
spi-dw-mmio.c | -rw-r--r-- | 3.2 KB |
spi-dw-pci.c | -rw-r--r-- | 3.5 KB |
spi-dw.c | -rw-r--r-- | 14.4 KB |
spi-dw.h | -rw-r--r-- | 6.1 KB |
spi-efm32.c | -rw-r--r-- | 11.8 KB |
spi-ep93xx.c | -rw-r--r-- | 24.3 KB |
spi-falcon.c | -rw-r--r-- | 10.5 KB |
spi-fsl-cpm.c | -rw-r--r-- | 10.1 KB |
spi-fsl-cpm.h | -rw-r--r-- | 1.6 KB |
spi-fsl-dspi.c | -rw-r--r-- | 18.8 KB |
spi-fsl-espi.c | -rw-r--r-- | 21.7 KB |
spi-fsl-lib.c | -rw-r--r-- | 4.3 KB |
spi-fsl-lib.h | -rw-r--r-- | 3.4 KB |
spi-fsl-spi.c | -rw-r--r-- | 22.6 KB |
spi-fsl-spi.h | -rw-r--r-- | 2.0 KB |
spi-gpio.c | -rw-r--r-- | 14.7 KB |
spi-img-spfi.c | -rw-r--r-- | 20.6 KB |
spi-imx.c | -rw-r--r-- | 33.7 KB |
spi-lm70llp.c | -rw-r--r-- | 9.0 KB |
spi-loopback-test.c | -rw-r--r-- | 24.3 KB |
spi-lp8841-rtc.c | -rw-r--r-- | 5.9 KB |
spi-meson-spifc.c | -rw-r--r-- | 11.3 KB |
spi-mpc512x-psc.c | -rw-r--r-- | 16.1 KB |
spi-mpc52xx-psc.c | -rw-r--r-- | 13.3 KB |
spi-mpc52xx.c | -rw-r--r-- | 14.1 KB |
spi-mt65xx.c | -rw-r--r-- | 20.1 KB |
spi-mxs.c | -rw-r--r-- | 14.2 KB |
spi-nuc900.c | -rw-r--r-- | 8.9 KB |
spi-oc-tiny.c | -rw-r--r-- | 8.6 KB |
spi-octeon.c | -rw-r--r-- | 6.2 KB |
spi-omap-100k.c | -rw-r--r-- | 12.4 KB |
spi-omap-uwire.c | -rw-r--r-- | 12.4 KB |
spi-omap2-mcspi.c | -rw-r--r-- | 38.6 KB |
spi-orion.c | -rw-r--r-- | 15.8 KB |
spi-pl022.c | -rw-r--r-- | 68.1 KB |
spi-ppc4xx.c | -rw-r--r-- | 13.6 KB |
spi-pxa2xx-dma.c | -rw-r--r-- | 8.7 KB |
spi-pxa2xx-pci.c | -rw-r--r-- | 5.6 KB |
spi-pxa2xx.c | -rw-r--r-- | 45.9 KB |
spi-pxa2xx.h | -rw-r--r-- | 4.0 KB |
spi-qup.c | -rw-r--r-- | 26.5 KB |
spi-rb4xx.c | -rw-r--r-- | 5.1 KB |
spi-rockchip.c | -rw-r--r-- | 21.6 KB |
spi-rspi.c | -rw-r--r-- | 34.2 KB |
spi-s3c24xx-fiq.S | -rw-r--r-- | 2.9 KB |
spi-s3c24xx-fiq.h | -rw-r--r-- | 671 bytes |
spi-s3c24xx.c | -rw-r--r-- | 15.1 KB |
spi-s3c64xx.c | -rw-r--r-- | 37.4 KB |
spi-sc18is602.c | -rw-r--r-- | 7.7 KB |
spi-sh-hspi.c | -rw-r--r-- | 6.5 KB |
spi-sh-msiof.c | -rw-r--r-- | 34.3 KB |
spi-sh-sci.c | -rw-r--r-- | 4.7 KB |
spi-sh.c | -rw-r--r-- | 11.9 KB |
spi-sirf.c | -rw-r--r-- | 35.5 KB |
spi-st-ssc4.c | -rw-r--r-- | 11.5 KB |
spi-sun4i.c | -rw-r--r-- | 11.4 KB |
spi-sun6i.c | -rw-r--r-- | 11.8 KB |
spi-tegra114.c | -rw-r--r-- | 33.1 KB |
spi-tegra20-sflash.c | -rw-r--r-- | 16.3 KB |
spi-tegra20-slink.c | -rw-r--r-- | 33.6 KB |
spi-test.h | -rw-r--r-- | 5.3 KB |
spi-ti-qspi.c | -rw-r--r-- | 15.5 KB |
spi-tle62x0.c | -rw-r--r-- | 7.2 KB |
spi-topcliff-pch.c | -rw-r--r-- | 46.6 KB |
spi-txx9.c | -rw-r--r-- | 11.0 KB |
spi-xcomm.c | -rw-r--r-- | 5.8 KB |
spi-xilinx.c | -rw-r--r-- | 14.1 KB |
spi-xlp.c | -rw-r--r-- | 11.4 KB |
spi-xtensa-xtfpga.c | -rw-r--r-- | 4.0 KB |
spi-zynqmp-gqspi.c | -rw-r--r-- | 33.2 KB |
spi.c | -rw-r--r-- | 84.7 KB |
spidev.c | -rw-r--r-- | 21.1 KB |
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