From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932661AbcFCMsB (ORCPT ); Fri, 3 Jun 2016 08:48:01 -0400 Received: from mail-vk0-f66.google.com ([209.85.213.66]:33589 "EHLO mail-vk0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932156AbcFCMr7 (ORCPT ); Fri, 3 Jun 2016 08:47:59 -0400 MIME-Version: 1.0 In-Reply-To: References: <1464230275-25791-1-git-send-email-iamjoonsoo.kim@lge.com> <1464230275-25791-2-git-send-email-iamjoonsoo.kim@lge.com> From: Joonsoo Kim Date: Fri, 3 Jun 2016 21:47:52 +0900 Message-ID: Subject: Re: [PATCH v2 2/7] mm/page_owner: initialize page owner without holding the zone lock To: Vlastimil Babka Cc: Andrew Morton , Mel Gorman , Minchan Kim , Alexander Potapenko , Hugh Dickins , Michal Hocko , LKML , Linux Memory Management List , Joonsoo Kim Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2016-06-03 19:23 GMT+09:00 Vlastimil Babka : > On 05/26/2016 04:37 AM, js1304@gmail.com wrote: >> >> From: Joonsoo Kim >> >> It's not necessary to initialized page_owner with holding the zone lock. >> It would cause more contention on the zone lock although it's not >> a big problem since it is just debug feature. But, it is better >> than before so do it. This is also preparation step to use stackdepot >> in page owner feature. Stackdepot allocates new pages when there is no >> reserved space and holding the zone lock in this case will cause deadlock. >> >> Signed-off-by: Joonsoo Kim >> --- >> mm/compaction.c | 3 +++ >> mm/page_alloc.c | 2 -- >> mm/page_isolation.c | 9 ++++++--- >> 3 files changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/mm/compaction.c b/mm/compaction.c >> index 8e013eb..6043ef8 100644 >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -20,6 +20,7 @@ >> #include >> #include >> #include >> +#include >> #include "internal.h" >> >> #ifdef CONFIG_COMPACTION >> @@ -80,6 +81,8 @@ static void map_pages(struct list_head *list) >> arch_alloc_page(page, order); >> kernel_map_pages(page, nr_pages, 1); >> kasan_alloc_pages(page, order); >> + >> + set_page_owner(page, order, __GFP_MOVABLE); >> if (order) >> split_page(page, order); >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 5134f46..1b1ca57 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -2507,8 +2507,6 @@ int __isolate_free_page(struct page *page, unsigned >> int order) >> zone->free_area[order].nr_free--; >> rmv_page_order(page); >> >> - set_page_owner(page, order, __GFP_MOVABLE); >> - >> /* Set the pageblock if the isolated page is at least a pageblock >> */ >> if (order >= pageblock_order - 1) { >> struct page *endpage = page + (1 << order) - 1; >> diff --git a/mm/page_isolation.c b/mm/page_isolation.c >> index 612122b..927f5ee 100644 >> --- a/mm/page_isolation.c >> +++ b/mm/page_isolation.c >> @@ -7,6 +7,7 @@ >> #include >> #include >> #include >> +#include >> #include "internal.h" >> >> #define CREATE_TRACE_POINTS >> @@ -108,8 +109,6 @@ static void unset_migratetype_isolate(struct page >> *page, unsigned migratetype) >> if (pfn_valid_within(page_to_pfn(buddy)) && >> !is_migrate_isolate_page(buddy)) { >> __isolate_free_page(page, order); >> - kernel_map_pages(page, (1 << order), 1); >> - set_page_refcounted(page); >> isolated_page = page; >> } >> } >> @@ -128,8 +127,12 @@ static void unset_migratetype_isolate(struct page >> *page, unsigned migratetype) >> zone->nr_isolate_pageblock--; >> out: >> spin_unlock_irqrestore(&zone->lock, flags); >> - if (isolated_page) >> + if (isolated_page) { >> + kernel_map_pages(page, (1 << order), 1); > > > So why we don't need the other stuff done by e.g. map_pages()? For example > arch_alloc_page() and kasan_alloc_pages(). Maybe kasan_free_pages() (called > below via __free_pages() I assume) now doesn't check if the allocation part > was done. But maybe it will start doing that? > > See how the multiple places doing similar stuff is fragile? :( I answered it in reply of comment of patch 1. >> + set_page_refcounted(page); >> + set_page_owner(page, order, __GFP_MOVABLE); >> __free_pages(isolated_page, order); > > > This mixing of "isolated_page" and "page" is not a bug, but quite ugly. > Can't isolated_page variable just be a bool? > Looks better. I will do it. Thanks. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f198.google.com (mail-yw0-f198.google.com [209.85.161.198]) by kanga.kvack.org (Postfix) with ESMTP id 175D46B025F for ; Fri, 3 Jun 2016 08:47:54 -0400 (EDT) Received: by mail-yw0-f198.google.com with SMTP id x189so211785031ywe.2 for ; Fri, 03 Jun 2016 05:47:54 -0700 (PDT) Received: from mail-vk0-x244.google.com (mail-vk0-x244.google.com. [2607:f8b0:400c:c05::244]) by mx.google.com with ESMTPS id t127si969346vkg.203.2016.06.03.05.47.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 Jun 2016 05:47:53 -0700 (PDT) Received: by mail-vk0-x244.google.com with SMTP id m81so13156699vka.0 for ; Fri, 03 Jun 2016 05:47:53 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1464230275-25791-1-git-send-email-iamjoonsoo.kim@lge.com> <1464230275-25791-2-git-send-email-iamjoonsoo.kim@lge.com> From: Joonsoo Kim Date: Fri, 3 Jun 2016 21:47:52 +0900 Message-ID: Subject: Re: [PATCH v2 2/7] mm/page_owner: initialize page owner without holding the zone lock Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Andrew Morton , Mel Gorman , Minchan Kim , Alexander Potapenko , Hugh Dickins , Michal Hocko , LKML , Linux Memory Management List , Joonsoo Kim 2016-06-03 19:23 GMT+09:00 Vlastimil Babka : > On 05/26/2016 04:37 AM, js1304@gmail.com wrote: >> >> From: Joonsoo Kim >> >> It's not necessary to initialized page_owner with holding the zone lock. >> It would cause more contention on the zone lock although it's not >> a big problem since it is just debug feature. But, it is better >> than before so do it. This is also preparation step to use stackdepot >> in page owner feature. Stackdepot allocates new pages when there is no >> reserved space and holding the zone lock in this case will cause deadlock. >> >> Signed-off-by: Joonsoo Kim >> --- >> mm/compaction.c | 3 +++ >> mm/page_alloc.c | 2 -- >> mm/page_isolation.c | 9 ++++++--- >> 3 files changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/mm/compaction.c b/mm/compaction.c >> index 8e013eb..6043ef8 100644 >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -20,6 +20,7 @@ >> #include >> #include >> #include >> +#include >> #include "internal.h" >> >> #ifdef CONFIG_COMPACTION >> @@ -80,6 +81,8 @@ static void map_pages(struct list_head *list) >> arch_alloc_page(page, order); >> kernel_map_pages(page, nr_pages, 1); >> kasan_alloc_pages(page, order); >> + >> + set_page_owner(page, order, __GFP_MOVABLE); >> if (order) >> split_page(page, order); >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 5134f46..1b1ca57 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -2507,8 +2507,6 @@ int __isolate_free_page(struct page *page, unsigned >> int order) >> zone->free_area[order].nr_free--; >> rmv_page_order(page); >> >> - set_page_owner(page, order, __GFP_MOVABLE); >> - >> /* Set the pageblock if the isolated page is at least a pageblock >> */ >> if (order >= pageblock_order - 1) { >> struct page *endpage = page + (1 << order) - 1; >> diff --git a/mm/page_isolation.c b/mm/page_isolation.c >> index 612122b..927f5ee 100644 >> --- a/mm/page_isolation.c >> +++ b/mm/page_isolation.c >> @@ -7,6 +7,7 @@ >> #include >> #include >> #include >> +#include >> #include "internal.h" >> >> #define CREATE_TRACE_POINTS >> @@ -108,8 +109,6 @@ static void unset_migratetype_isolate(struct page >> *page, unsigned migratetype) >> if (pfn_valid_within(page_to_pfn(buddy)) && >> !is_migrate_isolate_page(buddy)) { >> __isolate_free_page(page, order); >> - kernel_map_pages(page, (1 << order), 1); >> - set_page_refcounted(page); >> isolated_page = page; >> } >> } >> @@ -128,8 +127,12 @@ static void unset_migratetype_isolate(struct page >> *page, unsigned migratetype) >> zone->nr_isolate_pageblock--; >> out: >> spin_unlock_irqrestore(&zone->lock, flags); >> - if (isolated_page) >> + if (isolated_page) { >> + kernel_map_pages(page, (1 << order), 1); > > > So why we don't need the other stuff done by e.g. map_pages()? For example > arch_alloc_page() and kasan_alloc_pages(). Maybe kasan_free_pages() (called > below via __free_pages() I assume) now doesn't check if the allocation part > was done. But maybe it will start doing that? > > See how the multiple places doing similar stuff is fragile? :( I answered it in reply of comment of patch 1. >> + set_page_refcounted(page); >> + set_page_owner(page, order, __GFP_MOVABLE); >> __free_pages(isolated_page, order); > > > This mixing of "isolated_page" and "page" is not a bug, but quite ugly. > Can't isolated_page variable just be a bool? > Looks better. I will do it. Thanks. -- 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/ . Don't email: email@kvack.org