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From: Johannes Berg <johannes@sipsolutions.net>
To: Tiwei Bie <tiwei.bie@linux.dev>,
	richard@nod.at,  anton.ivanov@cambridgegreys.com
Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
	 benjamin@sipsolutions.net, arnd@arndb.de,
	tiwei.btw@antgroup.com
Subject: Re: [PATCH v2 05/10] um: Determine sleep based on need_resched()
Date: Thu, 11 Sep 2025 11:27:04 +0200	[thread overview]
Message-ID: <78c8e39d9719a26c6e492e895b070794eb8218ea.camel@sipsolutions.net> (raw)
In-Reply-To: <20250810055136.897712-6-tiwei.bie@linux.dev> (sfid-20250810_075306_773702_0F58F2CF)

On Sun, 2025-08-10 at 13:51 +0800, Tiwei Bie wrote:
> 
>  void um_idle_sleep(void)
>  {
> -	if (time_travel_mode != TT_MODE_OFF)
> +	if (time_travel_mode != TT_MODE_OFF) {
>  		time_travel_sleep();
> -	else
> +	} else {
> +		raw_local_irq_enable();
>  		os_idle_sleep();
> +		raw_local_irq_disable();
> +	}

This seems wrong, with it, lockdep gets really unhappy, and if I remove
this change it seems to work OK?

I'll note that arch_cpu_idle() for x86 also doesn't change anything with
interrupts.

Was there something else that required this change that I'm missing?

johannes

  parent reply	other threads:[~2025-09-11  9:27 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-10  5:51 [PATCH v2 00/10] um: Add SMP support Tiwei Bie
2025-08-10  5:51 ` [PATCH v2 01/10] um: Stop tracking virtual CPUs via mm_cpumask() Tiwei Bie
2025-08-10  5:51 ` [PATCH v2 02/10] um: Remove unused cpu_data and current_cpu_data macros Tiwei Bie
2025-08-10  5:51 ` [PATCH v2 03/10] um: vdso: Implement __vdso_getcpu() via syscall Tiwei Bie
2025-09-10 11:59   ` Johannes Berg
2025-09-11  4:29     ` Tiwei Bie
2025-09-21 20:00     ` Thomas Weißschuh
2025-09-22  4:50       ` Tiwei Bie
2025-09-22 12:05         ` Thomas Weißschuh
2025-09-22 12:12           ` Johannes Berg
2025-09-22 14:01             ` Thomas Weißschuh
2025-09-22 15:14               ` Johannes Berg
2025-09-22 16:04                 ` Thomas Weißschuh
2025-09-22 17:07                   ` Johannes Berg
2025-09-25 17:08                     ` Thomas Weißschuh
2025-08-10  5:51 ` [PATCH v2 04/10] um: Turn signals_* into thread-local variables Tiwei Bie
2025-09-10 12:15   ` Johannes Berg
2025-09-11  4:34     ` Tiwei Bie
2025-09-11  7:37       ` Benjamin Berg
2025-09-11  8:06         ` Benjamin Berg
2025-09-12  0:30           ` Tiwei Bie
2025-09-12  7:58             ` Benjamin Berg
2025-09-12 13:27               ` Tiwei Bie
2025-09-11  9:44         ` Johannes Berg
2025-09-11 10:35           ` Benjamin Berg
2025-08-10  5:51 ` [PATCH v2 05/10] um: Determine sleep based on need_resched() Tiwei Bie
2025-09-10 12:10   ` Johannes Berg
2025-09-11  4:39     ` Tiwei Bie
2025-09-11  6:59       ` Johannes Berg
2025-09-12  0:59         ` Tiwei Bie
2025-09-11  9:27   ` Johannes Berg [this message]
2025-09-12  0:54     ` Tiwei Bie
2025-08-10  5:51 ` [PATCH v2 06/10] um: Define timers on a per-CPU basis Tiwei Bie
2025-08-10  9:49   ` kernel test robot
2025-08-10  5:51 ` [PATCH v2 07/10] um: Remove unused ipi_pipe field from cpuinfo_um Tiwei Bie
2025-08-10  5:51 ` [PATCH v2 08/10] um: Add initial SMP support Tiwei Bie
2025-09-11  9:32   ` Johannes Berg
2025-09-12  0:45     ` Tiwei Bie
2025-09-12  7:58       ` Johannes Berg
2025-08-10  5:51 ` [PATCH v2 09/10] asm-generic: percpu: Add assembly guard Tiwei Bie
2025-09-10 12:12   ` Johannes Berg
2025-08-10  5:51 ` [PATCH v2 10/10] um: Enable SMP support on x86 Tiwei Bie

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