From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC][PATCH 01/11] asm-generic/tlb: Provide a comment Date: Wed, 19 Sep 2018 15:12:54 +0200 Message-ID: <20180919131254.GI24124@hirez.programming.kicks-ass.net> References: <20180913092110.817204997@infradead.org> <20180913092811.894806629@infradead.org> <20180914164857.GG6236@arm.com> <20180919115158.GD24124@hirez.programming.kicks-ass.net> <20180919122328.GB22723@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180919122328.GB22723@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon Cc: aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, heiko.carstens@de.ibm.com List-Id: linux-arch.vger.kernel.org On Wed, Sep 19, 2018 at 01:23:29PM +0100, Will Deacon wrote: > > > > + * which (when !need_flush_all; fullmm will have start = end = ~0UL) provides > > > > + * the range that needs to be flushed to cover the pages to be freed. > > > > > > I don't understand the mention of need_flush_all here -- I didn't think it > > > was used by the core code at all. > > > > The core does indeed not use that flag; but if the architecture set > > that, the range is still ignored. > > > > Can you suggest clearer wording? > > The range is only ignored if the default tlb_flush() implementation is used > though, right? Since this text is about the fields that tlb_flush() can use, > I think we can just delete the part in brackets. Well, any architecture that actually uses need_flush_all will obviously require a tlb_flush implementation that looks at it. But OK, I'll remove the note. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:42908 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731620AbeISSuy (ORCPT ); Wed, 19 Sep 2018 14:50:54 -0400 Date: Wed, 19 Sep 2018 15:12:54 +0200 From: Peter Zijlstra Subject: Re: [RFC][PATCH 01/11] asm-generic/tlb: Provide a comment Message-ID: <20180919131254.GI24124@hirez.programming.kicks-ass.net> References: <20180913092110.817204997@infradead.org> <20180913092811.894806629@infradead.org> <20180914164857.GG6236@arm.com> <20180919115158.GD24124@hirez.programming.kicks-ass.net> <20180919122328.GB22723@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180919122328.GB22723@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, heiko.carstens@de.ibm.com Message-ID: <20180919131254.KAA4gJKM9UfLd8wfZ0_gXd_zu-tk8Zq6qfmQYj6NX4A@z> On Wed, Sep 19, 2018 at 01:23:29PM +0100, Will Deacon wrote: > > > > + * which (when !need_flush_all; fullmm will have start = end = ~0UL) provides > > > > + * the range that needs to be flushed to cover the pages to be freed. > > > > > > I don't understand the mention of need_flush_all here -- I didn't think it > > > was used by the core code at all. > > > > The core does indeed not use that flag; but if the architecture set > > that, the range is still ignored. > > > > Can you suggest clearer wording? > > The range is only ignored if the default tlb_flush() implementation is used > though, right? Since this text is about the fields that tlb_flush() can use, > I think we can just delete the part in brackets. Well, any architecture that actually uses need_flush_all will obviously require a tlb_flush implementation that looks at it. But OK, I'll remove the note.