Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) client-ip=2620:137:e000::3:5;
Message-ID: <57b3b129-9d89-4008-b160-b77116c4e8e0@efficios.com>
Date:   Wed, 25 Oct 2023 10:04:46 -0400
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [RFC PATCH v2 1/2] sched/fair: Introduce UTIL_FITS_CAPACITY
 feature (v2)
Content-Language: en-US
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Valentin Schneider <vschneid@redhat.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Swapnil Sapkal <Swapnil.Sapkal@amd.com>,
        Aaron Lu <aaron.lu@intel.com>, Chen Yu <yu.c.chen@intel.com>,
        Tim Chen <tim.c.chen@intel.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        "Gautham R . Shenoy" <gautham.shenoy@amd.com>, x86@kernel.org
References: <20231019160523.1582101-1-mathieu.desnoyers@efficios.com>
 <20231019160523.1582101-2-mathieu.desnoyers@efficios.com>
 <20231025075646.GB37471@noisy.programming.kicks-ass.net>
From:   Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
In-Reply-To: <20231025075646.GB37471@noisy.programming.kicks-ass.net>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2023-10-25 03:56, Peter Zijlstra wrote:
> On Thu, Oct 19, 2023 at 12:05:22PM -0400, Mathieu Desnoyers wrote:
> 
>> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
>> index e93e006a942b..463e75084aed 100644
>> --- a/kernel/sched/sched.h
>> +++ b/kernel/sched/sched.h
>> @@ -2090,6 +2090,11 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features =
>>   
>>   #endif /* SCHED_DEBUG */
>>   
>> +static __always_inline bool sched_util_fits_capacity_active(void)
>> +{
>> +	return sched_feat(UTIL_EST) && sched_feat(UTIL_FITS_CAPACITY);
>> +}
> 
> This generates pretty terrible code; it cannot collapse this into a
> single branch. And since sched_feat is at best a debug interface for
> people who knows wtf they're doing, just make this UTIL_FITS_CAPACITY
> with a comment or so.

OK, change applied for the next round, thanks!

Mathieu


-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com