https://github.com/torvalds/linux
Revision 6a942f5780545ebd11aca8b3ac4b163397962322 authored by Valentin Schneider on 07 July 2021, 16:33:38 UTC, committed by Vasily Gorbik on 08 July 2021, 20:12:18 UTC
S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the preempt_count of the requested CPU's idle task: it unconditionally writes to the current CPU's. This clearly conflicts with idle_threads_init(), which intends to initialize *all* the idle tasks, including their preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count). Unfortunately, it seems the way s390 does things doesn't let us initialize every possible CPU's preempt_count early on, as the pages where this resides are only allocated when a CPU is brought up and are freed when it is brought down. Let the arch-specific code set a CPU's preempt_count when its lowcore is allocated, and turn init_idle_preempt_count() into an empty stub. Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
1 parent 4ee471f
Tip revision: 6a942f5780545ebd11aca8b3ac4b163397962322 authored by Valentin Schneider on 07 July 2021, 16:33:38 UTC
s390: preempt: Fix preempt_count initialization
s390: preempt: Fix preempt_count initialization
Tip revision: 6a942f5
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certs | ||
crypto | ||
drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
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net | ||
samples | ||
scripts | ||
security | ||
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usr | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
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.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 19.7 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 98.6 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 593.7 KB |
Makefile | -rw-r--r-- | 64.4 KB |
README | -rw-r--r-- | 727 bytes |
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