From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 185DDCA0ED1 for ; Mon, 11 Aug 2025 18:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:To:Subject :MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vlcR8Fwn5ADV0f3lvSmAv3ffA1ULrZcSZjdY6wWbXb4=; b=BznCLpRMaCpX9K de9TXWtZTCI9fO8iZyQGhpHWn72Ib2i4t0j8kt7jyArO37wHV1QRK+ZWR7xBihmjiyrnURCjsnBJx wEPl9hZvLMqcfpH8IYDUmErmtWuUqiLDoFCOrb/cFjIrIydG6QSgc3CimbjaQltqLFwUxS/GTRzuA yn2H1St4V5hlNl80ykbiCue7Cg8ZIuRUGMpW4dnukFwu5KRPtMTLFS7wDvAnVIf41u9X/mIhVhcq/ c2FbUKZ09gYESNJ9NZSJX1OzZqnkUEiCh1A7UqJHefYcMvmLugzOWDdl3IrT6Daifi51G2PHeE/dc j8hZ9utl00XVvTsttzRg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ulXar-00000008q0Y-3lvh; Mon, 11 Aug 2025 18:50:01 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ulUyl-00000008JrJ-3Fgg for linux-arm-kernel@lists.infradead.org; Mon, 11 Aug 2025 16:02:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0293A267F; Mon, 11 Aug 2025 09:02:23 -0700 (PDT) Received: from [10.1.28.163] (e137867.arm.com [10.1.28.163]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 271C53F738; Mon, 11 Aug 2025 09:02:26 -0700 (PDT) Message-ID: Date: Mon, 11 Aug 2025 17:02:25 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH -next v7 5/7] arm64: entry: Refactor preempt_schedule_irq() check code To: Jinjie Ruan References: <20250729015456.3411143-1-ruanjinjie@huawei.com> <20250729015456.3411143-6-ruanjinjie@huawei.com> <44fd646c-4e31-4ca6-9e22-f715ad19e0d7@arm.com> From: Ada Couprie Diaz Content-Language: en-US Organization: Arm Ltd. In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250811_090231_854734_7529E56D X-CRM114-Status: GOOD ( 18.95 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, sstabellini@kernel.org, puranjay@kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, liaochang1@huawei.com, oleg@redhat.com, kristina.martsenko@arm.com, linux-kernel@vger.kernel.org, broonie@kernel.org, chenl311@chinatelecom.cn, xen-devel@lists.xenproject.org, leitao@debian.org, ryan.roberts@arm.com, akpm@linux-foundation.org, mbenes@suse.cz, will@kernel.org, ardb@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 06/08/2025 07:39, Jinjie Ruan wrote: > On 2025/8/5 23:06, Ada Couprie Diaz wrote: >> Hi Jinjie, >> >> On 29/07/2025 02:54, Jinjie Ruan wrote: >>> ARM64 requires an additional check whether to reschedule on return >>> from interrupt. So add arch_irqentry_exit_need_resched() as the default >>> NOP implementation and hook it up into the need_resched() condition in >>> raw_irqentry_exit_cond_resched(). This allows ARM64 to implement >>> the architecture specific version for switching over to >>> the generic entry code. >>> [...] >> I've had some trouble reviewing this patch : on the one hand because >> I didn't notice `arch_irqentry_exit_need_resched()` was added in >> the common entry code, which is on me ! >> On the other hand, I felt that the patch itself was a bit disconnected : >> we add `arch_irqentry_exit_need_resched()` in the common entry code, >> with a default NOP, but in the same function we add to arm64, >> while mentioning that this is for arm64's additional checks, >> which we only implement in patch 7. > Yes, it does. > >> Would it make sense to move the `arch_irqentry_exit_need_resched()` >> part of the patch to patch 7, so that the introduction and >> arch-specific implementation appear together ? >> To me it seems easier to wrap my head around, as it would look like >> "Move arm64 to generic entry, but it does additional checks : add a new >> arch-specific function controlling re-scheduling, defaulting to true, >> and implement it for arm64". I feel it could help making patch 7's >> commit message clearer as well. >> >> From what I gathered on the archive `arch_irqentry_exit_need_resched()` >> being added here was suggested previously, so others might not have the >> same opinion. > Yes, introduce `arch_irqentry_exit_need_resched()` here may help > understand the patch's refactoring purpose. I can see that as well. I shared my opinion in case it could be useful, but as I mentioned in my reply to the cover : it's not a big issue and I'm happy for `arch_irqentry_exit_need_resched()` to be implemented here if that makes more sense ! >> Maybe improving the commit message and comment for this would be enough >> as well, as per my suggestions above. > Thank you! I'll improve the commit message and comment. > My pleasure ! Ada