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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F3BEC433FF for ; Mon, 12 Aug 2019 19:02:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5BF820684 for ; Mon, 12 Aug 2019 19:02:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726768AbfHLTCa (ORCPT ); Mon, 12 Aug 2019 15:02:30 -0400 Received: from mga18.intel.com ([134.134.136.126]:63529 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbfHLTC3 (ORCPT ); Mon, 12 Aug 2019 15:02:29 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Aug 2019 12:01:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,378,1559545200"; d="scan'208";a="194025844" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by fmsmga001.fm.intel.com with ESMTP; 12 Aug 2019 12:01:58 -0700 Date: Mon, 12 Aug 2019 12:01:58 -0700 From: Ira Weiny To: John Hubbard Cc: Andrew Morton , Jason Gunthorpe , Dan Williams , Matthew Wilcox , Jan Kara , Theodore Ts'o , Michal Hocko , Dave Chinner , linux-xfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 11/19] mm/gup: Pass follow_page_context further down the call stack Message-ID: <20190812190158.GA20634@iweiny-DESK2.sc.intel.com> References: <20190809225833.6657-1-ira.weiny@intel.com> <20190809225833.6657-12-ira.weiny@intel.com> <57000521-cc09-9c33-9fa4-1fae5a3972c2@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57000521-cc09-9c33-9fa4-1fae5a3972c2@nvidia.com> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 09, 2019 at 05:18:31PM -0700, John Hubbard wrote: > On 8/9/19 3:58 PM, ira.weiny@intel.com wrote: > > From: Ira Weiny > > > > In preparation for passing more information (vaddr_pin) into > > follow_page_pte(), follow_devmap_pud(), and follow_devmap_pmd(). > > > > Signed-off-by: Ira Weiny [snip] > > @@ -786,7 +782,8 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) > > static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > > unsigned long start, unsigned long nr_pages, > > unsigned int gup_flags, struct page **pages, > > - struct vm_area_struct **vmas, int *nonblocking) > > + struct vm_area_struct **vmas, int *nonblocking, > > + struct vaddr_pin *vaddr_pin) > > I didn't expect to see more vaddr_pin arg passing, based on the commit > description. Did you want this as part of patch 9 or 10 instead? If not, > then let's mention it in the commit description. Yea that does seem out of place now that I look at it. I'll add to the commit message because this is really getting vaddr_pin into the context _and_ passing it down the stack. With all the rebasing I may have squashed something I did not mean to. But I think this patch is ok because it is not to complicated to see what is going on. Thanks, Ira > > > { > > long ret = 0, i = 0; > > struct vm_area_struct *vma = NULL; > > @@ -797,6 +794,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > > > > VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); > > > > + ctx.vaddr_pin = vaddr_pin; > > + > > /* > > * If FOLL_FORCE is set then do not force a full fault as the hinting > > * fault information is unrelated to the reference behaviour of a task > > @@ -1025,7 +1024,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, > > lock_dropped = false; > > for (;;) { > > ret = __get_user_pages(tsk, mm, start, nr_pages, flags, pages, > > - vmas, locked); > > + vmas, locked, vaddr_pin); > > if (!locked) > > /* VM_FAULT_RETRY couldn't trigger, bypass */ > > return ret; > > @@ -1068,7 +1067,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, > > lock_dropped = true; > > down_read(&mm->mmap_sem); > > ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED, > > - pages, NULL, NULL); > > + pages, NULL, NULL, vaddr_pin); > > if (ret != 1) { > > BUG_ON(ret > 1); > > if (!pages_done) > > @@ -1226,7 +1225,7 @@ long populate_vma_page_range(struct vm_area_struct *vma, > > * not result in a stack expansion that recurses back here. > > */ > > return __get_user_pages(current, mm, start, nr_pages, gup_flags, > > - NULL, NULL, nonblocking); > > + NULL, NULL, nonblocking, NULL); > > } > > > > /* > > @@ -1311,7 +1310,7 @@ struct page *get_dump_page(unsigned long addr) > > > > if (__get_user_pages(current, current->mm, addr, 1, > > FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma, > > - NULL) < 1) > > + NULL, NULL) < 1) > > return NULL; > > flush_cache_page(vma, addr, page_to_pfn(page)); > > return page; > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index bc1a07a55be1..7e09f2f17ed8 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -916,8 +916,9 @@ static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, > > } > > > > struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, > > - pmd_t *pmd, int flags, struct dev_pagemap **pgmap) > > + pmd_t *pmd, int flags, struct follow_page_context *ctx) > > { > > + struct dev_pagemap **pgmap = &ctx->pgmap; > > unsigned long pfn = pmd_pfn(*pmd); > > struct mm_struct *mm = vma->vm_mm; > > struct page *page; > > @@ -1068,8 +1069,9 @@ static void touch_pud(struct vm_area_struct *vma, unsigned long addr, > > } > > > > struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, > > - pud_t *pud, int flags, struct dev_pagemap **pgmap) > > + pud_t *pud, int flags, struct follow_page_context *ctx) > > { > > + struct dev_pagemap **pgmap = &ctx->pgmap; > > unsigned long pfn = pud_pfn(*pud); > > struct mm_struct *mm = vma->vm_mm; > > struct page *page; > > diff --git a/mm/internal.h b/mm/internal.h > > index 0d5f720c75ab..46ada5279856 100644 > > --- a/mm/internal.h > > +++ b/mm/internal.h > > @@ -12,6 +12,34 @@ > > #include > > #include > > > > +struct follow_page_context { > > + struct dev_pagemap *pgmap; > > + unsigned int page_mask; > > + struct vaddr_pin *vaddr_pin; > > +}; > > + > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > > +struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, > > + pmd_t *pmd, int flags, struct follow_page_context *ctx); > > +struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, > > + pud_t *pud, int flags, struct follow_page_context *ctx); > > +#else > > +static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma, > > + unsigned long addr, pmd_t *pmd, int flags, > > + struct follow_page_context *ctx) > > +{ > > + return NULL; > > +} > > + > > +static inline struct page *follow_devmap_pud(struct vm_area_struct *vma, > > + unsigned long addr, pud_t *pud, int flags, > > + struct follow_page_context *ctx) > > +{ > > + return NULL; > > +} > > +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ > > + > > + > > /* > > * The set of flags that only affect watermark checking and reclaim > > * behaviour. This is used by the MM to obey the caller constraints > > > > > > > thanks, > -- > John Hubbard > NVIDIA