From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51216566C53; Tue, 29 Sep 2026 19:25:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790709905; cv=none; b=cktKvgoGe3lpAmtdlQZkPBjwGf502D1LDBPZGAPHSYl2I11hZAe5kJmSl56rMlFKlPRsM7+DlBhIjK1eWikhBACmNtuY9Aa2VkxGRv92ldo8+CuoqztxEW1i8vrsIxQcw28nXax359Zl4YwvhS2jRWuUswvXXLewwvSORvPrYFg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790709905; c=relaxed/simple; bh=YpVkw7xPpOTZe7PrRB9vYQcuDFdlpzpqyM0i2DHRCH8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=S5WFBteJg6GbD+HObkJHyug2/8rIuKuUGk/ZIG7kGgh2i46oGWbLluIjBhVixZHoDoyDPf0VVLZSlb7HPDmYA1YOVWCJqE011DZjxlC1jPbG6f7fYKzOPTn98OxZr+Pb8Uh5FuE3xo7xe1bYFWwgRjomRqj4tlfNHdGh5c5tQO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YID+rB8x; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YID+rB8x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8AC01F000FF; Tue, 29 Sep 2026 19:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790709903; bh=/L11jNXsHZIT6aH1fo02FiVZj0vopibIiBuH4+iamIs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YID+rB8xmlOy/NbjJLtfDaab4iB49iMG6q3NmALjCh35sT6haS5rSGhZoHzw9qRIG oK6wtuz/4ZOvoNgtm2pKJMH7Ghbm77YiBx0LKrh/tIgiuCrQZAslyO4GqHriOYod// 3rsXieQfOEW7zehaffPAC3LUUX9Pa1i/XtWPILunJAERfw3Fxx1/cnP8+MJscLwT0G q+bdMtyP2ubFrtYSe+h+jtTpqjXPQLVjBgXVCxuvDvjbGj6f/tYddrjO26WfA9ULMd VAdqnrWt1bKrFcf+8Ei9Jpkpl+U3yK5RWpzUmovcnosWfr1HxpXlv+YPO3XiKCDhJ0 vWtSInjgqknww== Date: Tue, 29 Sep 2026 09:25:02 -1000 From: Tejun Heo To: Andrea Righi Cc: David Vernet , Changwoo Min , Emil Tsalapatis , David Dai , Yonghong Song , Alexei Starovoitov , bpf@vger.kernel.org, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH sched_ext/for-7.4] sched_ext: Work around pahole 1.32 dropping scx_bpf_task_set_lazy_resched() from BTF Message-ID: References: <7c139810be5ffc9764ed4236efc28794@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Sep 29, 2026 at 09:19:50PM +0200, Andrea Righi wrote: > First of all thanks for figuring this out, it was really annoying, I've been > holding pahole to 1.31 because of this. > > I also looked a bit and it seems to be triggered specifically by the bool type. > This is with clang 22.1.8 on x86_64 without barrier_data and only changing the > type: > > bool movl %esi, %ebp -> dropped by pahole > u32 movl %esi, %ebp -> ok > u64 movq %rsi, %r15 -> ok > > With u32 the generated code is identical to the bool case, but clang keeps the > RSI entry range, so pahole is happy. > > Should we just change lazy to u32 (or use a u64 flags) instead of using > barrier_data()? I mean, bool is the right and I'm hoping clang can be fixed and the workaround seems to work, so keep it as-is unless there are other reasons to change it (e.g. this becomes a wider interface taking u64 flags or sth like that)? Thanks. -- tejun