From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030215AbcFBUMx (ORCPT ); Thu, 2 Jun 2016 16:12:53 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50720 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751336AbcFBUMv (ORCPT ); Thu, 2 Jun 2016 16:12:51 -0400 Date: Thu, 2 Jun 2016 13:12:50 -0700 From: Andrew Morton To: "Aneesh Kumar K.V" Cc: mpe@ellerman.id.au, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Benjamin Herrenschmidt Subject: Re: [PATCH 4/4] powerpc/mm/radix: Implement tlb mmu gather flush efficiently Message-Id: <20160602131250.e4d43401e7eade277bc4476a@linux-foundation.org> In-Reply-To: <1464860389-29019-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1464860389-29019-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1464860389-29019-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Jun 2016 15:09:49 +0530 "Aneesh Kumar K.V" wrote: > Now that we track page size in mmu_gather, we can use address based > tlbie format when doing a tlb_flush(). We don't do this if we are > invalidating the full address space. > > ... > > void radix__tlb_flush(struct mmu_gather *tlb) > { > + int psize = 0; > struct mm_struct *mm = tlb->mm; > - radix__flush_tlb_mm(mm); > + int page_size = tlb->page_size; > + > + psize = radix_get_mmu_psize(page_size); > + if (psize == -1) > + /* unknown page size */ > + goto flush_mm; > + > + if (!tlb->fullmm && !tlb->need_flush_all) > + radix__flush_tlb_range_psize(mm, tlb->start, tlb->end, psize); > + else > +flush_mm: > + radix__flush_tlb_mm(mm); That's kinda ugly. What about void radix__tlb_flush(struct mmu_gather *tlb) { int psize = 0; struct mm_struct *mm = tlb->mm; int page_size = tlb->page_size; psize = radix_get_mmu_psize(page_size); if (psize != -1 && !tlb->fullmm && !tlb->need_flush_all) radix__flush_tlb_range_psize(mm, tlb->start, tlb->end, psize); else radix__flush_tlb_mm(mm); } ? We lost the comment, but that can be neatly addressed by documenting radix_get_mmu_psize() (of course!). Please send along a comment to do this and I'll add it in. --- a/arch/powerpc/mm/tlb-radix.c~powerpc-mm-radix-implement-tlb-mmu-gather-flush-efficiently-fix +++ a/arch/powerpc/mm/tlb-radix.c @@ -265,13 +265,9 @@ void radix__tlb_flush(struct mmu_gather int page_size = tlb->page_size; psize = radix_get_mmu_psize(page_size); - if (psize == -1) - /* unknown page size */ - goto flush_mm; - if (!tlb->fullmm && !tlb->need_flush_all) + if (psize != -1 && !tlb->fullmm && !tlb->need_flush_all) radix__flush_tlb_range_psize(mm, tlb->start, tlb->end, psize); else -flush_mm: radix__flush_tlb_mm(mm); } _ I'll await feedback from the other PPC developers before doing anything further on this patchset. hm, no ppc mailing lists were cc'ed. Regrettable.