AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-11-24 06:50:58 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
c228fe74bb
linux_dsm_epyc7002/arch/arm/kernel
History
Valentin Schneider 3c51d82d0b sched/core: Initialize the idle task with preemption disabled 
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ]

As pointed out by commit

  de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:55:50 +02:00
..
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
arch_timer.c ARM: 8913/1: arch_timer: include <asm/arch_timer.h> 2019-10-27 21:14:43 +00:00
armksyms.c crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h 2020-05-08 15:32:17 +10:00
asm-offsets.c ARM: 9075/1: kernel: Fix interrupted SMC calls 2021-05-22 11:40:53 +02:00
atags_compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
atags_parse.c ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
atags_proc.c ARM: 8973/1: Add missing newline terminator to kernel message 2020-05-07 20:53:10 +01:00
atags.h ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
bios32.c ARM/PCI: Remove unused fields from struct hw_pci 2020-09-18 22:39:09 +01:00
bugs.c treewide: fix typos of SPDX-License-Identifier 2019-06-01 18:29:58 +02:00
cpuidle.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
crash_dump.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
debug.S ARM: 9005/1: debug: Select flow control for all debug UARTs 2020-09-15 14:35:28 +01:00
devtree.c ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
dma-isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
early_printk.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
efi.c mm/pgtable: drop pgtable_t variable from pte_fn_t functions 2019-07-12 11:05:46 -07:00
elf.c arm32/64/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK 2020-04-20 19:42:19 +02:00
entry-armv.S ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode 2020-12-30 11:53:43 +01:00
entry-common.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-ftrace.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-header.S ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h 2020-05-03 17:30:24 +01:00
entry-v7m.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
fiq.c arm: fix the flush_icache_range arguments in set_fiq_handler 2020-06-08 11:05:57 -07:00
fiqasm.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
ftrace.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
head-common.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head-inflate-data.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
head-nommu.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head.S ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section 2021-05-19 10:13:18 +02:00
hibernate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
hw_breakpoint.c ARM: 9064/1: hw_breakpoint: Do not directly check the event's overflow_handler hook 2021-05-19 10:13:01 +02:00
hyp-stub.S arm: Remove the ability to set HYP vectors outside of the decompressor 2020-03-24 10:56:05 +00:00
insn.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
io.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.c ARM: Remove custom IRQ stat accounting 2020-09-17 16:37:28 +01:00
isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
iwmmxt.h ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler 2021-03-17 17:06:26 +01:00
iwmmxt.S ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler 2021-03-17 17:06:26 +01:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kgdb.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
machine_kexec.c ARM: kexec: fix oops after TLB are invalidated 2021-02-17 11:02:24 +01:00
Makefile Linux 5.5-rc1 2019-12-10 10:11:00 +01:00
module-plts.c ARM: 8910/1: fix missing declartion of module_frob_arch_sections 2019-10-27 21:14:38 +00:00
module.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
opcodes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
paravirt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
patch.c arm/patch: Fix !MMU compile 2020-02-11 12:56:27 +01:00
perf_callchain.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
perf_event_v6.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_event_v7.c arm_pmu: Fix write counter incorrect in ARMv7 big-endian mode 2021-07-14 16:55:39 +02:00
perf_event_xscale.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_regs.c perf/arch: Remove perf_sample_data::regs_user_copy 2020-11-09 18:12:34 +01:00
pj4-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
process.c sched/idle: Fix arch_cpu_idle() vs tracing 2020-11-24 16:47:35 +01:00
psci_smp.c ARM: 8919/1: make unexported functions static 2019-10-31 16:58:52 +00:00
ptrace.c arm: switch to ->regset_get() 2020-07-27 14:31:09 -04:00
reboot.c ARM: Use reboot_cpu instead of hardcoding it to 0 2020-03-25 12:59:33 +01:00
reboot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
relocate_kernel.S ARM: kexec: fix oops after TLB are invalidated 2021-02-17 11:02:24 +01:00
return_address.c ARM: 8918/2: only build return_address() if needed 2019-11-15 22:21:07 +00:00
setup.c ARM: 9081/1: fix gcc-10 thumb2-kernel regression 2021-06-30 08:47:16 -04:00
signal.c ARM: ensure the signal page contains defined contents 2021-02-17 11:02:24 +01:00
signal.h ARM: 8920/1: share get_signal_page from signal.c to process.c 2019-10-31 16:58:53 +00:00
sigreturn_codes.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
sleep.S ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used 2019-02-26 11:32:54 +00:00
smccc-call.S ARM: 9075/1: kernel: Fix interrupted SMC calls 2021-05-22 11:40:53 +02:00
smp_scu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_tlb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_twd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp.c sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
stacktrace.c ARM: 8992/1: Fix unwind_frame for clang-built kernels 2020-07-21 16:33:40 +01:00
suspend.c ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend() 2021-05-22 11:40:52 +02:00
swp_emulate.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
sys_arm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sys_oabi-compat.c ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled 2021-03-04 11:38:10 +01:00
tcm.c ARM: 8925/1: tcm: include <asm/tcm.h> for missing declarations 2019-10-31 16:58:56 +00:00
thumbee.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
time.c ARM/time: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-05-15 22:54:57 +02:00
topology.c ARM, sched/topology: Revert back to default scheduler topology 2020-08-19 10:49:47 +02:00
traps.c maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
unwind.c arm: add loglvl to unwind_backtrace() 2020-06-09 09:39:10 -07:00
v7m.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vdso.c ARM: 8987/1: VDSO: Fix incorrect clock_gettime64 2020-07-21 16:32:55 +01:00
vmlinux-xip.lds.S arm/build: Assert for unwanted sections 2020-09-01 10:03:18 +02:00
vmlinux.lds.S arm/build: Always handle .ARM.exidx and .ARM.extab sections 2020-10-27 11:32:21 -07:00
xscale-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00