From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2FBE51AD9F8 for ; Mon, 14 Oct 2024 13:10:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728911448; cv=none; b=XmEKjsWtwqsx4x2KKbGXtAHjZi7rMDBRG4AY7XMvbXhX+sn8y9kiwLxlD5+boLL/xYogU2tkCcBGrrgAJvAKOWdVIITD0O6QkEHX6uTe1vUSLaQ/ORM2eqBEph+eCVtxBKfgV5nC53CDTf0SQza5G4wWvDijeRnznebdKR/g5I4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728911448; c=relaxed/simple; bh=YlnMitl1nLOteyh8gA+2LBlWbZHa6L6A0MLvuZ7ayak=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PlzDtrjKbXEmDxwzRmPNLmntNwu4WnAqp7wgTCPy1SawPD+ADAIVdhtY1lKKtVRirOupG69Awex22T1hZGqrd++APnaBWFdSN9Ez0pT6LObz6whBYe6+oIZ6U0bxJs1Hk1ZVonMkEWuZylpXxpCcgOggW9/a1FoMdDawLmNwZe8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W/N1SIdC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="W/N1SIdC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ECABC4CEC6; Mon, 14 Oct 2024 13:10:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728911447; bh=YlnMitl1nLOteyh8gA+2LBlWbZHa6L6A0MLvuZ7ayak=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W/N1SIdCG1aBBJJORv5NeHppZz0CcrlCsVaqL5XsMwJANKnLFSeaDYGJ28SVevTtA wmKbAXRv5Almy7vC5SHjDBZdkkuIkqCds7XUaM1ThVIAG28grmZWopCIPlyJZ1tIHn 98oMgDpG3uPPMlDcuMf1NPMmPgGHkBCDoBEz5ABEzvkwhXzDqndK+aeT0Bc3HmgaJ7 YcfkwnBl3mpkIHkOoHWgYCJnuC1CEU+Jmae/cVLN497GcfhnYmGV1j5Z8j94VckNHi 5jNv6/yR/V9vb2l5fIobcC2d7EhHnD7q5TKQOCnoqxvmy1N1ZJRB4rw0CJm0iHIjXD OlQ5X7OZCT2NQ== Date: Mon, 14 Oct 2024 14:10:43 +0100 From: Will Deacon To: Ryo Takakura Cc: catalin.marinas@arm.com, broonie@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: Remove the check for CONFIG_TINY_RCU Message-ID: <20241014131042.GA17353@willie-the-truck> References: <20240914090040.166671-1-ryotkkr98@gmail.com> 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: <20240914090040.166671-1-ryotkkr98@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) On Sat, Sep 14, 2024 at 06:00:40PM +0900, Ryo Takakura wrote: > Since the commit 4b3dc9679cf77 ("arm64: force CONFIG_SMP=y and remove > redundant #ifdefs"), arm64 defaults to CONFIG_SMP but TINY_RCU is cofigured > only for !SMP systems. > > Remove the check for CONFIG_TINY_RCU as it should always be false. > > Signed-off-by: Ryo Takakura > --- > arch/arm64/kernel/entry-common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c > index b77a15955f28..a9765364fc67 100644 > --- a/arch/arm64/kernel/entry-common.c > +++ b/arch/arm64/kernel/entry-common.c > @@ -40,7 +40,7 @@ static __always_inline void __enter_from_kernel_mode(struct pt_regs *regs) > { > regs->exit_rcu = false; > > - if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) { > + if (is_idle_task(current)) { > lockdep_hardirqs_off(CALLER_ADDR0); > ct_irq_enter(); > trace_hardirqs_off_finish(); I think this code was deliberately written to follow kernel/entry/common.c as closely as possible, as we should be able to switch over to that at some point. Come to think of it, Mark, what work is needed before we can move to the generic code? Is there anything you need a hand with? Will