Re: [PATCH v0.9.1 3/6] sched/umcg: implement UMCG syscalls

From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Peter Oskolkov <posk@posk.io>, Ingo Molnar <mingo@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-api@vger.kernel.org, Paul Turner <pjt@google.com>,
	Ben Segall <bsegall@google.com>, Peter Oskolkov <posk@google.com>,
	Andrei Vagin <avagin@google.com>, Jann Horn <jannh@google.com>,
	Thierry Delisle <tdelisle@uwaterloo.ca>
Subject: Re: [PATCH v0.9.1 3/6] sched/umcg: implement UMCG syscalls
Date: Sat, 27 Nov 2021 01:45:20 +0100	[thread overview]
Message-ID: <87tufyfmu7.ffs@tglx> (raw)
In-Reply-To: <YaFY0KqfPhmZjK7n@hirez.programming.kicks-ass.net>

On Fri, Nov 26 2021 at 22:59, Peter Zijlstra wrote:
> On Fri, Nov 26, 2021 at 10:08:14PM +0100, Thomas Gleixner wrote:
>> > +		if (timo)
>> > +			hrtimer_sleeper_start_expires(&timeout, HRTIMER_MODE_ABS);
>> > +
>> > +		freezable_schedule();
>> 
>> You can replace the whole hrtimer foo with
>> 
>>                 if (!schedule_hrtimeout_range_clock(timo ? &timo : NULL,
>>                                                     tsk->timer_slack_ns,
>>                                                     HRTIMER_MODE_ABS,
>>                                                     tsk->umcg_clock)) {
>>                 	ret = -ETIMEOUT;
>>                         break;
>>                 }
>
> That seems to loose the freezable crud.. then again, since we're
> interruptible, that shouldn't matter. Lemme go do that.

We could add a freezable wrapper for that if necessary.

Thanks,

        tglx