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 B7BBCC28B2E for ; Thu, 13 Mar 2025 12:57:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XWNwVYjn1+JrCFskQnoojnEo6YjFGgML+DSzXtBeIb4=; b=At1qbOz2jjPwVV 3E5JGUVBrkuPnJWnFSBZqZ/pCUNReeU8ISLWRFU/LsTNnhmdD/pzeY3tqk2Le/MLjkeFFrFqq8Y0g kmBN3tnLuQfSR1TExspV9p2mJSFxB+lGrbBCv9MCF7QL0JVfY74KsODwNs+0FIL/W+LsdubnjkW3i C0MLZz589vgvmVASPAzEVhzwULckO3GD2P7TnXrJNzormU67wSNdAzRzJI+3V2MO+1Johp07h9zX7 6CU4cxlDXTDwbpqBrNwLLOV3nRiBzOHsEb7ur/gYNxmCdml/NmQvSs6wBQdkfTPAlDzCe3TcGFHM+ xBSyt4ziOz9KSKHZwPHg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tsi84-0000000BIwQ-20Is; Thu, 13 Mar 2025 12:57:40 +0000 Received: from mail-wr1-x431.google.com ([2a00:1450:4864:20::431]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tsi7z-0000000BIv8-3KN2 for linux-riscv@lists.infradead.org; Thu, 13 Mar 2025 12:57:37 +0000 Received: by mail-wr1-x431.google.com with SMTP id ffacd0b85a97d-394780e98easo611005f8f.1 for ; Thu, 13 Mar 2025 05:57:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1741870654; x=1742475454; darn=lists.infradead.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=oU2CWGwDlIJhGLUqCxoni4cHhWUsK2iDFsgYYpF/oTQ=; b=CnG0HB36bE2FGGiBdzn0H+DiohO0cwaNzmdsKiRJkXn7wjHIq0bXnODdwJe/Tv3NH2 n2r70QdUsoMux9Sb0+FlNb7Y7QZl5f6CmxSiUbI9dh+IRdz+0GyD5YmHOFJ6SyfG+pcP YMhIK6VEPR0nLvpKlCYqjXdFADLY7SaPM3uywKfBA4SGG93J/zHNEYMnavSMVgzmT6P6 QyCXfowmsUjMLVXqPpekQO+CcCR4WuzTHwpTVSRR3ageR0ixdzwUgiBj5KwwbhG5ps8z 9m8xQZoZ0cwqtSZagU3pRdYx0RihsRwJpnwIaknXTKfsoF1XEY2e1L+YyACz2WwpABxo 7Syg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741870654; x=1742475454; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oU2CWGwDlIJhGLUqCxoni4cHhWUsK2iDFsgYYpF/oTQ=; b=NRmCGyvYCOeArf4xvVk5/MqaocRNBoClBFdlp1hNfc2ouzm/xBuu82KXWtu8To7i4G cxTFDK/mOajCpSNndMRlIDfZWWZRt6yjB25OpCpou+D8ZUZzf9HTu7RnFVPLVVboeqRh 0Qf8+/IDiwyGeADFKCqiaTvq7jQCdnzUnxfZQgOW8RpB3AHQ2DBQZ0pt737WPQcYorKe xoBCqLLfPi9NDDTry56RL6kL5WnPBZGXIWzKrriJ10vcy6wuJXyYcwuffw4wL2wlHxay LsrkkutRL/UaAnPO46YnXvK5SW2+PV+opgGVMUG1INbO0dvyBz4zkBtzdWWqadQVVpHL 6wzA== X-Forwarded-Encrypted: i=1; AJvYcCWhYCzXqpvK1/w4Ji4GzJrFSQ0ZcrEnt7yJTYrlCUp6h+/B2nUTFWAcQmsaU5CBmMYdwFcI7hcuE4SfIA==@lists.infradead.org X-Gm-Message-State: AOJu0YwDVwMtoEcd+qD/JD6IWYFtOatTqFjlIrVEJZ4L1g9yalQSDYM+ hVANLAB43d50ERHPFujbO6RZviYH2cJx9LGtttc5x4m5k+3vOxkrtTysObhlNE8= X-Gm-Gg: ASbGncvKG58f73PNcNfDMTYjk5qca1aoGSXj6l5wT0YI3JkwDm8ygxc6RECowHz3nsO X72Md4bySSc3KNm/k3Mn+6rLXl4fGX+NAHvAqstqxe1nsqDj1s1pAy4krzsEpnDgWf10Dal4Sud Rg1U7QMcpzTX0XctrEkPNae9TgX4kOl1vNRMK3HPMJ05WATOgr5YEP3b0md96SQ+MN1f/15oH6U jfLgUht6pLsaXOwsJvAgkgRL47LvL7c37Q+zeAKViNtd1cAqy1Bs1whJfNjsQBLCU/td0mKU3r3 Kd2gl3lGfIbz7DO5aSDAOKtbHMIedjOm X-Google-Smtp-Source: AGHT+IGM1DblGtxykFocIp33D2K47p5ADdU4DE4GFvOo3U3iDj70FwK79o4wmAKz0GgKu55I89czxg== X-Received: by 2002:a5d:64ac:0:b0:390:e889:d1cf with SMTP id ffacd0b85a97d-39132dc561cmr20667619f8f.37.1741870654174; Thu, 13 Mar 2025 05:57:34 -0700 (PDT) Received: from localhost ([2a02:8308:a00c:e200::59a5]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-395c82c2690sm2044096f8f.25.2025.03.13.05.57.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Mar 2025 05:57:33 -0700 (PDT) Date: Thu, 13 Mar 2025 13:57:32 +0100 From: Andrew Jones To: =?utf-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= Cc: Paul Walmsley , Palmer Dabbelt , Anup Patel , Atish Patra , Shuah Khan , Jonathan Corbet , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-kselftest@vger.kernel.org, Samuel Holland Subject: Re: [PATCH v3 05/17] riscv: misaligned: use on_each_cpu() for scalar misaligned access probing Message-ID: <20250313-311b94f9bafe73bcd41158a1@orel> References: <20250310151229.2365992-1-cleger@rivosinc.com> <20250310151229.2365992-6-cleger@rivosinc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250310151229.2365992-6-cleger@rivosinc.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250313_055735_833686_2054809F X-CRM114-Status: GOOD ( 19.34 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Mar 10, 2025 at 04:12:12PM +0100, Cl=E9ment L=E9ger wrote: > schedule_on_each_cpu() was used without any good reason while documented > as very slow. This call was in the boot path, so better use > on_each_cpu() for scalar misaligned checking. Vector misaligned check > still needs to use schedule_on_each_cpu() since it requires irqs to be > enabled but that's less of a problem since this code is ran in a kthread. > Add a comment to explicit that. > = > Signed-off-by: Cl=E9ment L=E9ger > --- > arch/riscv/kernel/traps_misaligned.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > = > diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/tra= ps_misaligned.c > index 90ac74191357..ffac424faa88 100644 > --- a/arch/riscv/kernel/traps_misaligned.c > +++ b/arch/riscv/kernel/traps_misaligned.c > @@ -616,6 +616,11 @@ bool check_vector_unaligned_access_emulated_all_cpus= (void) > return false; > } > = > + /* > + * While being documented as very slow, schedule_on_each_cpu() is used > + * since kernel_vector_begin() that is called inside the vector code > + * expects irqs to be enabled or it will panic(). which expects > + */ > schedule_on_each_cpu(check_vector_unaligned_access_emulated); > = > for_each_online_cpu(cpu) > @@ -636,7 +641,7 @@ bool check_vector_unaligned_access_emulated_all_cpus(= void) > = > static bool unaligned_ctl __read_mostly; > = > -static void check_unaligned_access_emulated(struct work_struct *work __a= lways_unused) > +static void check_unaligned_access_emulated(void *arg __always_unused) > { > int cpu =3D smp_processor_id(); > long *mas_ptr =3D per_cpu_ptr(&misaligned_access_speed, cpu); > @@ -677,7 +682,7 @@ bool check_unaligned_access_emulated_all_cpus(void) > * accesses emulated since tasks requesting such control can run on any > * CPU. > */ > - schedule_on_each_cpu(check_unaligned_access_emulated); > + on_each_cpu(check_unaligned_access_emulated, NULL, 1); > = > for_each_online_cpu(cpu) > if (per_cpu(misaligned_access_speed, cpu) > -- = > 2.47.2 > Reviewed-by: Andrew Jones _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv