From: Tejun Heo <tj@kernel.org>
To: Puranjay Mohan <puranjay@kernel.org>
Cc: bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
David Vernet <void@manifault.com>,
Andrea Righi <arighi@nvidia.com>,
Changwoo Min <changwoo@igalia.com>,
sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH bpf-next v4 0/3] bpf, x86: Support fetching AND/OR/XOR atomics in arena
Date: Thu, 15 Oct 2026 07:06:02 -1000 [thread overview]
Message-ID: <4e063370a5b974364587fabd04c1aaf7@kernel.org> (raw)
In-Reply-To: <20261014125017.1426212-1-puranjay@kernel.org>
Hello, Puranjay.
On Wed, Oct 14, 2026 at 05:50:10AM -0700, Puranjay Mohan wrote:
> A fetching AND/OR/XOR against arena memory is rejected on x86-64:
>
> BPF_ATOMIC stores into R1 arena is not allowed
- 1/3: A fetching atomic through a number now fails to load with an
empty verifier log, where it used to get the message above. That
seems problematic. Can that case keep an error message?
- 3/3: sched_ext/for-7.4 already synced a cid.bpf.h from scx which
probes for the fetching atomics and keeps the CAS loop as the
old-kernel fallback, so this conflicts with it. I'll pull
bpf/for-next into sched_ext/for-7.4 and we can do the modifications
on top.
For 1/3 and 2/3,
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
--
tejun
prev parent reply other threads:[~2026-10-15 17:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-14 12:50 [PATCH bpf-next v4 0/3] bpf, x86: Support fetching AND/OR/XOR atomics in arena Puranjay Mohan
2026-10-14 12:50 ` [PATCH bpf-next v4 1/3] " Puranjay Mohan
2026-10-14 12:50 ` [PATCH bpf-next v4 2/3] selftests/bpf: Test " Puranjay Mohan
2026-10-14 12:50 ` [PATCH bpf-next v4 3/3] sched_ext: Use fetching atomics for cmask instead of a cmpxchg loop Puranjay Mohan
2026-10-14 13:23 ` bot+bpf-ci
2026-10-14 13:34 ` Puranjay Mohan
2026-10-15 17:06 ` Tejun Heo [this message]
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