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[210.128.90.14]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-83a8b28be7fsm23462739f.11.2024.10.15.03.08.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Oct 2024 03:08:15 -0700 (PDT) From: Ryo Takakura To: will@kernel.org Cc: broonie@kernel.org, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, ryotkkr98@gmail.com Subject: Re: [PATCH] arm64: Remove the check for CONFIG_TINY_RCU Date: Tue, 15 Oct 2024 19:08:09 +0900 Message-Id: <20241015100809.15581-1-ryotkkr98@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241014131042.GA17353@willie-the-truck> References: <20241014131042.GA17353@willie-the-truck> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Will, On 2024-10-14, Will Deacon wrote: >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. Oh I see, thanks for taking a look at the patch! >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 If there is anything I can be of help, let me know! Sincerely, Ryo Takakura