From: Thomas Gleixner <tglx@kernel.org>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Calvin Owens <calvin@wbinvd.org>,
Peter Zijlstra <peterz@infradead.org>,
Anna-Maria Behnsen <anna-maria@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, John Stultz <jstultz@google.com>,
Stephen Boyd <sboyd@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, Sebastian Reichel <sre@kernel.org>,
linux-pm@vger.kernel.org, Pablo Neira Ayuso <pablo@netfilter.org>,
Florian Westphal <fw@strlen.de>, Phil Sutter <phil@nwl.cc>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org
Subject: Re: [patch 01/12] clockevents: Prevent timer interrupt starvation
Date: Tue, 07 Apr 2026 20:01:42 +0200 [thread overview]
Message-ID: <87ldey4pkp.ffs@tglx> (raw)
In-Reply-To: <87tstm4uss.ffs@tglx>
On Tue, Apr 07 2026 at 18:08, Thomas Gleixner wrote:
> On Tue, Apr 07 2026 at 16:00, Frederic Weisbecker wrote:
> As I had to introduce the flag and prevent the other scenraio I just
> consolidated everything into one code path.
Just for the record. This whole -ETIME handling is restricted to HPET
like devices where the hardware people decided it's a brilliant idea to
build a 'equal' comparator and then followed up by making the write
posted to reduce the costs of the write. The original direct write was
already flawed vs. NMI/SMI, but the delayed commit into the comparator
made it insanely broken.
AFAICT that's a handful devices in the zoo of clockevent IPs the kernel
supports, so I'm really not too worried about the impact of this change.
Any sane hardware will never hit that code path so no point for
optimizing for it.
Thanks,
tglx
next prev parent reply other threads:[~2026-04-07 18:01 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-07 8:54 [patch 00/12] hrtimers: Prevent hrtimer interrupt starvation Thomas Gleixner
2026-04-07 8:54 ` [patch 01/12] clockevents: Prevent timer " Thomas Gleixner
2026-04-07 9:42 ` Peter Zijlstra
2026-04-07 11:30 ` Thomas Gleixner
2026-04-07 11:49 ` Peter Zijlstra
2026-04-07 13:59 ` Thomas Gleixner
2026-04-07 14:00 ` Frederic Weisbecker
2026-04-07 16:08 ` Thomas Gleixner
2026-04-07 18:01 ` Thomas Gleixner [this message]
2026-04-07 14:33 ` Thomas Gleixner
2026-04-07 20:23 ` [tip: timers/urgent] " tip-bot2 for Thomas Gleixner
2026-04-07 8:54 ` [patch 02/12] hrtimer: Provide hrtimer_start_range_ns_user() Thomas Gleixner
2026-04-07 9:54 ` Peter Zijlstra
2026-04-07 11:32 ` Thomas Gleixner
2026-04-07 9:57 ` Peter Zijlstra
2026-04-07 11:34 ` Thomas Gleixner
2026-04-07 8:54 ` [patch 03/12] hrtimer: Use hrtimer_start_expires_user() for hrtimer sleepers Thomas Gleixner
2026-04-07 9:59 ` Peter Zijlstra
2026-04-07 8:54 ` [patch 04/12] posix-timers: Expand timer_[re]arm() callbacks with a boolean return value Thomas Gleixner
2026-04-07 10:00 ` Peter Zijlstra
2026-04-07 20:20 ` John Stultz
2026-04-07 8:54 ` [patch 05/12] posix-timers: Handle the timer_[re]arm() " Thomas Gleixner
2026-04-07 10:01 ` Peter Zijlstra
2026-04-07 8:54 ` [patch 06/12] posix-timers: Switch to hrtimer_start_expires_user() Thomas Gleixner
2026-04-07 10:01 ` Peter Zijlstra
2026-04-07 8:54 ` [patch 07/12] alarmtimer: Provide alarmtimer_start() Thomas Gleixner
2026-04-07 10:04 ` Peter Zijlstra
2026-04-07 11:34 ` Thomas Gleixner
2026-04-07 20:23 ` John Stultz
2026-04-07 8:54 ` [patch 08/12] alarmtimer: Convert posix timer functions to alarmtimer_start() Thomas Gleixner
2026-04-07 20:19 ` John Stultz
2026-04-07 8:54 ` [patch 09/12] fs/timerfd: Use the new alarm/hrtimer functions Thomas Gleixner
2026-04-07 10:09 ` Peter Zijlstra
2026-04-07 11:41 ` Thomas Gleixner
2026-04-07 8:55 ` [patch 10/12] power: supply: charger-manager: Switch to alarmtimer_start() Thomas Gleixner
2026-04-07 10:11 ` Peter Zijlstra
2026-04-07 8:55 ` [patch 11/12] netfilter: xt_IDLETIMER: " Thomas Gleixner
2026-04-07 8:55 ` [patch 12/12] alarmtimer: Remove unused interfaces Thomas Gleixner
2026-04-07 20:21 ` John Stultz
2026-04-07 14:43 ` [patch 00/12] hrtimers: Prevent hrtimer interrupt starvation Thomas Gleixner
2026-04-07 16:17 ` Thomas Gleixner
2026-04-07 17:38 ` Calvin Owens
2026-04-07 18:03 ` Thomas Gleixner
2026-04-07 18:35 ` Calvin Owens
2026-04-07 20:58 ` Thomas Gleixner
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