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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Frederic Weisbecker <frederic@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 45/47] tick/sched: Remove bogus boot "safety" check
Date: Mon,  4 Jan 2021 16:57:44 +0100	[thread overview]
Message-ID: <20210104155707.907106131@linuxfoundation.org> (raw)
In-Reply-To: <20210104155705.740576914@linuxfoundation.org>

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit ba8ea8e7dd6e1662e34e730eadfc52aa6816f9dd ]

can_stop_idle_tick() checks whether the do_timer() duty has been taken over
by a CPU on boot. That's silly because the boot CPU always takes over with
the initial clockevent device.

But even if no CPU would have installed a clockevent and taken over the
duty then the question whether the tick on the current CPU can be stopped
or not is moot. In that case the current CPU would have no clockevent
either, so there would be nothing to keep ticking.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20201206212002.725238293@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/time/tick-sched.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5c9fcc72460df..4419486d7413c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -916,13 +916,6 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
 		 */
 		if (tick_do_timer_cpu == cpu)
 			return false;
-		/*
-		 * Boot safety: make sure the timekeeping duty has been
-		 * assigned before entering dyntick-idle mode,
-		 * tick_do_timer_cpu is TICK_DO_TIMER_BOOT
-		 */
-		if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_BOOT))
-			return false;
 
 		/* Should not happen for nohz-full */
 		if (WARN_ON_ONCE(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
-- 
2.27.0




  parent reply	other threads:[~2021-01-04 16:09 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-04 15:56 [PATCH 5.4 00/47] 5.4.87-rc1 review Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 01/47] net/sched: sch_taprio: reset child qdiscs before freeing them Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 02/47] md/raid10: initialize r10_bio->read_slot before use Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 03/47] thermal/drivers/cpufreq_cooling: Update cpufreq_state only if state has changed Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 04/47] ext4: prevent creating duplicate encrypted filenames Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 05/47] ubifs: " Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 06/47] f2fs: " Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 07/47] fscrypt: add fscrypt_is_nokey_name() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 08/47] fscrypt: remove kernel-internal constants from UAPI header Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 09/47] vfio/pci: Move dummy_resources_list init in vfio_pci_probe() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 10/47] btrfs: fix race when defragmenting leads to unnecessary IO Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 11/47] ext4: dont remount read-only with errors=continue on reboot Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 12/47] KVM: x86: avoid incorrect writes to host MSR_IA32_SPEC_CTRL Greg Kroah-Hartman
2021-02-26 11:03   ` Thomas Lamprecht
2021-02-26 11:27     ` Paolo Bonzini
2021-02-26 12:59       ` Greg Kroah-Hartman
2021-02-26 14:15         ` Paolo Bonzini
2021-02-26 14:18           ` Thomas Lamprecht
2021-02-26 14:21             ` Paolo Bonzini
2021-01-04 15:57 ` [PATCH 5.4 13/47] KVM: SVM: relax conditions for allowing MSR_IA32_SPEC_CTRL accesses Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 14/47] KVM: x86: reinstate vendor-agnostic check on SPEC_CTRL cpuid bits Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 15/47] powerpc/bitops: Fix possible undefined behaviour with fls() and fls64() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 16/47] jffs2: Allow setting rp_size to zero during remounting Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 17/47] jffs2: Fix NULL pointer dereference in rp_size fs option parsing Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 18/47] scsi: block: Fix a race in the runtime power management code Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 19/47] uapi: move constants from <linux/kernel.h> to <linux/const.h> Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 20/47] tools headers UAPI: Sync linux/const.h with the kernel headers Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 21/47] null_blk: Fix zone size initialization Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 22/47] of: fix linker-section match-table corruption Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 23/47] cgroup: Fix memory leak when parsing multiple source parameters Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 24/47] scsi: cxgb4i: Fix TLS dependency Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 25/47] Bluetooth: hci_h5: close serdev device and free hu in h5_close Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 26/47] reiserfs: add check for an invalid ih_entry_count Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 27/47] misc: vmw_vmci: fix kernel info-leak by initializing dbells in vmci_ctx_get_chkpt_doorbells() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 28/47] media: gp8psk: initialize stats at power control logic Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 29/47] f2fs: fix shift-out-of-bounds in sanity_check_raw_super() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 30/47] ALSA: seq: Use bool for snd_seq_queue internal flags Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 31/47] ALSA: rawmidi: Access runtime->avail always in spinlock Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 32/47] bfs: dont use WARNING: string when its just info Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 33/47] fcntl: Fix potential deadlock in send_sig{io, urg}() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 34/47] rtc: sun6i: Fix memleak in sun6i_rtc_clk_init Greg Kroah-Hartman
2021-01-06 13:07   ` Pavel Machek
2021-01-04 15:57 ` [PATCH 5.4 35/47] module: set MODULE_STATE_GOING state when a module fails to load Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 36/47] quota: Dont overflow quota file offsets Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 37/47] rtc: pl031: fix resource leak in pl031_probe Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 38/47] powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe() Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 39/47] i3c master: fix missing destroy_workqueue() on error in i3c_master_register Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 40/47] NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 41/47] f2fs: avoid race condition for shrinker count Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 42/47] module: delay kobject uevent until after module init call Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 43/47] fs/namespace.c: WARN if mnt_count has become negative Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 44/47] um: ubd: Submit all data segments atomically Greg Kroah-Hartman
2021-01-04 15:57 ` Greg Kroah-Hartman [this message]
2021-01-04 15:57 ` [PATCH 5.4 46/47] ALSA: pcm: Clear the full allocated memory at hw_params Greg Kroah-Hartman
2021-01-04 15:57 ` [PATCH 5.4 47/47] dm verity: skip verity work if I/O error when system is shutting down Greg Kroah-Hartman
2021-01-05  6:07 ` [PATCH 5.4 00/47] 5.4.87-rc1 review Daniel Díaz
2021-01-05 16:39 ` Shuah Khan
2021-01-05 18:17 ` Guenter Roeck

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