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From: Roman Gushchin <roman.gushchin@linux.dev>
To: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,  linux-mm@kvack.org,
  bpf@vger.kernel.org,  Suren Baghdasaryan <surenb@google.com>,  Johannes
 Weiner <hannes@cmpxchg.org>,  Michal Hocko <mhocko@suse.com>,  David
 Rientjes <rientjes@google.com>,  Matt Bobrowski
 <mattbobrowski@google.com>,  Song Liu <song@kernel.org>,  Kumar Kartikeya
 Dwivedi <memxor@gmail.com>,  Alexei Starovoitov <ast@kernel.org>,  Andrew
 Morton <akpm@linux-foundation.org>,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 13/14] sched: psi: implement bpf_psi_create_trigger()
 kfunc
In-Reply-To: <c1b71664-91c0-439c-9cae-7407fa5b0358@linux.dev> (Martin KaFai
	Lau's message of "Fri, 22 Aug 2025 12:57:20 -0700")
References: <20250818170136.209169-1-roman.gushchin@linux.dev>
	<20250818170136.209169-14-roman.gushchin@linux.dev>
	<CAEf4BzaSLWB1xpCjX35oxg2ySvvgRvEmQ01PtXv+xEz-Zkz07w@mail.gmail.com>
	<87ect5lde2.fsf@linux.dev>
	<c1b71664-91c0-439c-9cae-7407fa5b0358@linux.dev>
Date: Mon, 25 Aug 2025 09:56:52 -0700
Message-ID: <87h5xvxru3.fsf@linux.dev>
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Martin KaFai Lau <martin.lau@linux.dev> writes:

> On 8/20/25 5:36 PM, Roman Gushchin wrote:
>> It will. Idk how big of a problem it is, given that the caller needs
>> a trusted reference to bpf_psi. Also, is there a simple way to constrain
>> it? Wdyt?
>
> The bpf qdisc has the kfunc filtering. Take a look at the
> bpf_qdisc_kfunc_filter in bpf_qdisc.c.

Thanks! I'll take a look.