Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751364AbbEYUaS (ORCPT ); Mon, 25 May 2015 16:30:18 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:57810 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751134AbbEYUaP (ORCPT ); Mon, 25 May 2015 16:30:15 -0400 From: Arnd Bergmann To: Catalin Marinas Cc: Jungseok Lee , Catalin Marinas , "barami97@gmail.com" , Will Deacon , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [RFC PATCH 2/2] arm64: Implement vmalloc based thread_info allocator Date: Mon, 25 May 2015 22:29:40 +0200 Message-ID: <5601369.jDWtB6nFJC@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <1432483340-23157-1-git-send-email-jungseoklee85@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:qYkpYH1JTQ9MAlvpDveJIGTA4UUmAqjdsjOS/2r0uZM9iinimek Q4Zu3HVHXnPQCrpnw2dYPV9gKSrnFkh1XbJCAa25pZiXba7sU+64nNoziZMDF+Vv5taWx+P s6jyPGzLSdLgkNrt2EiBK9hwuHW1pJUpMqvZ2+1++Isw8cWy3CKBNiF4wB6nca35nSgpBEW MrbWXrrtyxGjAB7gefDgg== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 27 On Monday 25 May 2015 19:47:15 Catalin Marinas wrote: > On 25 May 2015, at 13:01, Jungseok Lee wrote: > > >> Could the stack size be reduced to 8KB perhaps? > > > > I guess probably not. > > > > A commit, 845ad05e, says that 8KB is not enough to cover SpecWeb benchmark. > > We could go back to 8KB stacks if we implement support for separate IRQ > stack on arm64. It's not too complicated, we would have to use SP0 for (kernel) threads > and SP1 for IRQ handlers. I think most architectures that see a lot of benchmarks have moved to irqstacks at some point, that definitely sounds like a useful idea, even if the implementation turns out to be a bit more tricky than what you describe. There are a lot of workloads that would benefit from having lower per-thread memory cost. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/