Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Tejun Heo <htejun@gmail.com>
Date:   Mon, 12 Dec 2022 07:27:41 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     torvalds@linux-foundation.org, mingo@redhat.com,
        juri.lelli@redhat.com, vincent.guittot@linaro.org,
        dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com,
        mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com,
        ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
        martin.lau@kernel.org, joshdon@google.com, brho@google.com,
        pjt@google.com, derkling@google.com, haoluo@google.com,
        dvernet@meta.com, dschatzberg@meta.com, dskarlat@cs.cmu.edu,
        riel@surriel.com, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, kernel-team@meta.com
Subject: Re: [PATCHSET RFC] sched: Implement BPF extensible scheduler class
Message-ID: <Y5dkjYL/M+smPxeR@slm.duckdns.org>
References: <20221130082313.3241517-1-tj@kernel.org>
 <Y5b2btWFJeEfTyJg@hirez.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Y5b2btWFJeEfTyJg@hirez.programming.kicks-ass.net>
Precedence: bulk

Hello,

On Mon, Dec 12, 2022 at 10:37:50AM +0100, Peter Zijlstra wrote:
> Anyway, I hate all of this. Linus NAK'ed loadable schedulers a number of
> times in the past and this is just that again -- with the extra downside
> of the whole BPF thing on top  :/

Yeah, the whole BPF thing is what made this interesting for me and while
there still are frustrating shortcomings, BPF does make iteration and
deployment drastically safer and faster and we can try out ideas which
didn't seem feasible before with relative ease. Given the history, I suppose
some of the decision is upto Linus.

> You look to be exposing a ton of stuff I've so far even refused
> tracepoints for :-(

I tried to keep the exposure limited and am sure it can be much improved. If
you have specific ideas, I'm all ears.

> Anyway, I'm just back from a heavy dose of Covid and still taking it
> easy, but I'll go read through the whole thing, hopefully I'll finish
> before vanishing again for the x-mas break.

Mine wasn't too bad but it still sucked mightily. I wish a quick and full
recovery and thanks for taking a look.

-- 
tejun