From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Schwidefsky Subject: Re: [RFC][PATCH 4/6] arm, mm: Convert arm to generic tlb Date: Mon, 21 May 2012 09:47:09 +0200 Message-ID: <20120521094709.6036d868@de.ibm.com> References: <20110302175928.022902359@chello.nl> <20110302180259.109909335@chello.nl> <20120517030551.GA11623@linux-sh.org> <20120517093022.GA14666@arm.com> <20120517095124.GN23420@flint.arm.linux.org.uk> <1337254086.4281.26.camel@twins> <20120517160012.GB18593@arm.com> <1337271884.4281.46.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1337271884.4281.46.camel@twins> Sender: owner-linux-mm@kvack.org To: Peter Zijlstra Cc: Catalin Marinas , Russell King , Paul Mundt , Andrea Arcangeli , Thomas Gleixner , Rik van Riel , Ingo Molnar , "akpm@linux-foundation.org" , Linus Torvalds , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-mm@kvack.org" , Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Chris Metcalf List-Id: linux-arch.vger.kernel.org On Thu, 17 May 2012 18:24:44 +0200 Peter Zijlstra wrote: > On Thu, 2012-05-17 at 17:00 +0100, Catalin Marinas wrote: > > > BTW, looking at your tlb-unify branch, does tlb_remove_table() call > > tlb_flush/tlb_flush_mmu before freeing the tables? I can only see > > tlb_remove_page() doing this. On ARM, even UP, we need the TLB flushing > > after clearing the pmd and before freeing the pte page table (and > > ideally doing it less often than at every pte_free_tlb() call). > > No I don't think it does, so far the only archs using the RCU stuff are > ppc,sparc and s390 and none of those needed that (Xen might join them > soon though). But I will have to look and consider this more carefully. > I 'lost' most of the ppc/sparc/s390 details from memory to say this with > any certainty. s390 needs a TLB flush for the pgd, pud and pmd tables. See git commit cd94154cc6a28dd9dc271042c1a59c08d26da886 for the sad details. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:53152 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959Ab2EUHrr (ORCPT ); Mon, 21 May 2012 03:47:47 -0400 Received: from /spool/local by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 21 May 2012 08:47:42 +0100 Date: Mon, 21 May 2012 09:47:09 +0200 From: Martin Schwidefsky Subject: Re: [RFC][PATCH 4/6] arm, mm: Convert arm to generic tlb Message-ID: <20120521094709.6036d868@de.ibm.com> In-Reply-To: <1337271884.4281.46.camel@twins> References: <20110302175928.022902359@chello.nl> <20110302180259.109909335@chello.nl> <20120517030551.GA11623@linux-sh.org> <20120517093022.GA14666@arm.com> <20120517095124.GN23420@flint.arm.linux.org.uk> <1337254086.4281.26.camel@twins> <20120517160012.GB18593@arm.com> <1337271884.4281.46.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Catalin Marinas , Russell King , Paul Mundt , Andrea Arcangeli , Thomas Gleixner , Rik van Riel , Ingo Molnar , "akpm@linux-foundation.org" , Linus Torvalds , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-mm@kvack.org" , Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Chris Metcalf Message-ID: <20120521074709.EP8He2zNC2jh3BZh0qYAOs2adR7VvNLfhTfO9AVNSyM@z> On Thu, 17 May 2012 18:24:44 +0200 Peter Zijlstra wrote: > On Thu, 2012-05-17 at 17:00 +0100, Catalin Marinas wrote: > > > BTW, looking at your tlb-unify branch, does tlb_remove_table() call > > tlb_flush/tlb_flush_mmu before freeing the tables? I can only see > > tlb_remove_page() doing this. On ARM, even UP, we need the TLB flushing > > after clearing the pmd and before freeing the pte page table (and > > ideally doing it less often than at every pte_free_tlb() call). > > No I don't think it does, so far the only archs using the RCU stuff are > ppc,sparc and s390 and none of those needed that (Xen might join them > soon though). But I will have to look and consider this more carefully. > I 'lost' most of the ppc/sparc/s390 details from memory to say this with > any certainty. s390 needs a TLB flush for the pgd, pud and pmd tables. See git commit cd94154cc6a28dd9dc271042c1a59c08d26da886 for the sad details. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.