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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2538C54EE9 for ; Thu, 8 Sep 2022 16:08:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229748AbiIHQIa (ORCPT ); Thu, 8 Sep 2022 12:08:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231543AbiIHQI3 (ORCPT ); Thu, 8 Sep 2022 12:08:29 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF4F6FB8C9; Thu, 8 Sep 2022 09:08:26 -0700 (PDT) Date: Thu, 8 Sep 2022 18:08:23 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1662653305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3melgoxOyPm2WW+MNhQzQQlSABq+pMymGaM5BLeai9A=; b=Gp7zAcq+7nzep4nzUQTlLdgRIUFuc+CYrEawsF2uMxsBS2OCy2xJ6e9vaGHj5Akw1AhABk 1WOEwlsYw+6q/zbB6J46ir2O6l884q5B3EW5aXqiaNGvhko4xkD6wb83FtXsPQqho5nJxS IH9PHxxbCmX4xOycUcdzrelBnit9tcaUOlO3PRfU9JLFgkqgKngO6h9udx5HvJzuwRz+5n S9Dgwelw9WHpk1a2yfx1AOHnMRNEMQA65RwjsuXGRLRcSocegsJlbExOtjw9m9rZT/rhWJ 5A7XVgKn4T3q2+oAKJN/kK2yoU2MViFP0VmKgj/DXxpx/GeydYWqwPIneYOJ+g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1662653305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3melgoxOyPm2WW+MNhQzQQlSABq+pMymGaM5BLeai9A=; b=h8h0ZIYnWSbUEFvLZoVbXhjwdVf0TrAXuHPJieWzTDYNEf6tCIWWlU8leHT7kCHnJxQ6NW T1VaQjp3ssK/XyCQ== From: Sebastian Andrzej Siewior To: guoren@kernel.org Cc: arnd@arndb.de, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org, apatel@ventanamicro.com, atishp@atishpatra.org, palmer@dabbelt.com, paul.walmsley@sifive.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: Re: [PATCH V4 6/8] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Message-ID: References: <20220908022506.1275799-1-guoren@kernel.org> <20220908022506.1275799-7-guoren@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220908022506.1275799-7-guoren@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On 2022-09-07 22:25:04 [-0400], guoren@kernel.org wrote: > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index a07bb3b73b5b..a8a12b4ba1a9 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -433,6 +433,14 @@ config FPU > > If you don't know what to do here, say Y. > > +config IRQ_STACKS > + bool "Independent irq stacks" > + default y > + select HAVE_IRQ_EXIT_ON_IRQ_STACK > + help > + Add independent irq stacks for percpu to prevent kernel stack overflows. > + We may save some memory footprint by disabling IRQ_STACKS. Do you really think that it is needed to save memory here? Avoiding stack overflows in deep call chains is probably more important than saving ~8KiB per CPU. Sebastian