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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EDB7C6FA8F for ; Wed, 30 Aug 2023 19:08:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232022AbjH3TIQ (ORCPT ); Wed, 30 Aug 2023 15:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242484AbjH3Irc (ORCPT ); Wed, 30 Aug 2023 04:47:32 -0400 Received: from out-249.mta0.migadu.com (out-249.mta0.migadu.com [IPv6:2001:41d0:1004:224b::f9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8AF61B7 for ; Wed, 30 Aug 2023 01:47:28 -0700 (PDT) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693385247; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=P2UuBXuSjqeYTwWpl+jkQfX9DEW9Mf9mw9kyE4kUrZc=; b=XnwKpQIQYJNc5vIAe42TNhWJCe3Sh/kvslDgkBMl7nrFLtbTg31tkfKODXQzqDJvrbEg4n dxSZAncoEBYmPqPpsFLFPVWotQfyy3rnXVN4KzuAx683q3sDl3ZIMudJhRL9VdCyiuKY4/ +j25z7rJtYsMHo302ui92MfcDuToMi8= Date: Wed, 30 Aug 2023 16:47:18 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 12/12] hugetlb: batch TLB flushes when restoring vmemmap To: Mike Kravetz Cc: Muchun Song , Joao Martins , Oscar Salvador , David Hildenbrand , Miaohe Lin , David Rientjes , Anshuman Khandual , Naoya Horiguchi , Barry Song , Michal Hocko , Matthew Wilcox , Xiongchun Duan , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230825190436.55045-1-mike.kravetz@oracle.com> <20230825190436.55045-13-mike.kravetz@oracle.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <20230825190436.55045-13-mike.kravetz@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/8/26 03:04, Mike Kravetz wrote: > Update the hugetlb_vmemmap_restore path to take a 'batch' parameter that > indicates restoration is happening on a batch of pages. When set, use > the existing mechanism (VMEMMAP_REMAP_BULK_PAGES) to delay TLB flushing. > The routine hugetlb_vmemmap_restore_folios is the only user of this new > batch parameter and it will perform a global flush after all vmemmap is > restored. > > Signed-off-by: Mike Kravetz > --- > mm/hugetlb_vmemmap.c | 37 +++++++++++++++++++++++-------------- > 1 file changed, 23 insertions(+), 14 deletions(-) > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index a2fc7b03ac6b..d6e7440b9507 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -479,17 +479,19 @@ static int alloc_vmemmap_page_list(unsigned long start, unsigned long end, > * @end: end address of the vmemmap virtual address range that we want to > * remap. > * @reuse: reuse address. > + * @bulk: bulk operation, batch TLB flushes > * > * Return: %0 on success, negative error code otherwise. > */ > static int vmemmap_remap_alloc(unsigned long start, unsigned long end, > - unsigned long reuse) > + unsigned long reuse, bool bulk) I'd like to let vmemmap_remap_alloc pass VMEMMAP_REMAP_BULK_PAGES directly, in which case, we do not need to change this function if we want to introduce another flag in the future. I mean that change "bool bulk" to "unsigned long flags". > { > LIST_HEAD(vmemmap_pages); > struct vmemmap_remap_walk walk = { > .remap_pte = vmemmap_restore_pte, > .reuse_addr = reuse, > .vmemmap_pages = &vmemmap_pages, > + .flags = !bulk ? 0 : VMEMMAP_REMAP_BULK_PAGES, > }; > > /* See the comment in the vmemmap_remap_free(). */ > @@ -511,17 +513,7 @@ EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key); > static bool vmemmap_optimize_enabled = IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON); > core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0); > > -/** > - * hugetlb_vmemmap_restore - restore previously optimized (by > - * hugetlb_vmemmap_optimize()) vmemmap pages which > - * will be reallocated and remapped. > - * @h: struct hstate. > - * @head: the head page whose vmemmap pages will be restored. > - * > - * Return: %0 if @head's vmemmap pages have been reallocated and remapped, > - * negative error code otherwise. > - */ > -int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head) > +int __hugetlb_vmemmap_restore(const struct hstate *h, struct page *head, bool bulk) The same as here. > { > int ret; > unsigned long vmemmap_start = (unsigned long)head, vmemmap_end; > @@ -541,7 +533,7 @@ int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head) > * When a HugeTLB page is freed to the buddy allocator, previously > * discarded vmemmap pages must be allocated and remapping. > */ > - ret = vmemmap_remap_alloc(vmemmap_start, vmemmap_end, vmemmap_reuse); > + ret = vmemmap_remap_alloc(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk); > if (!ret) { > ClearHPageVmemmapOptimized(head); > static_branch_dec(&hugetlb_optimize_vmemmap_key); > @@ -550,12 +542,29 @@ int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head) > return ret; > } > > +/** > + * hugetlb_vmemmap_restore - restore previously optimized (by > + * hugetlb_vmemmap_optimize()) vmemmap pages which > + * will be reallocated and remapped. > + * @h: struct hstate. > + * @head: the head page whose vmemmap pages will be restored. > + * > + * Return: %0 if @head's vmemmap pages have been reallocated and remapped, > + * negative error code otherwise. > + */ > +int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head) > +{ > + return __hugetlb_vmemmap_restore(h, head, false); > +} > + > void hugetlb_vmemmap_restore_folios(const struct hstate *h, struct list_head *folio_list) > { > struct folio *folio; > > list_for_each_entry(folio, folio_list, lru) > - hugetlb_vmemmap_restore(h, &folio->page); > + (void)__hugetlb_vmemmap_restore(h, &folio->page, true); Pass VMEMMAP_REMAP_BULK_PAGES directly here. Thanks. > + > + flush_tlb_kernel_range(0, TLB_FLUSH_ALL); > } > > /* Return true iff a HugeTLB whose vmemmap should and can be optimized. */