Messages in this thread | | | Date | Fri, 19 Oct 2012 09:49:24 +0900 | From | Yasuaki Ishimatsu <> | Subject | Re: [PATCH 5/10] memory-hotplug : memory-hotplug: check page type in get_page_bootmem |
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Hi Kosaki,
Sorry for late reply.
2012/10/13 4:28, KOSAKI Motohiro wrote: > On Thu, Oct 4, 2012 at 10:32 PM, Yasuaki Ishimatsu > <isimatu.yasuaki@jp.fujitsu.com> wrote: >> The function get_page_bootmem() may be called more than one time to the same >> page. There is no need to set page's type, private if the function is not >> the first time called to the page. >> >> Note: the patch is just optimization and does not fix any problem. >> >> CC: David Rientjes <rientjes@google.com> >> CC: Jiang Liu <liuj97@gmail.com> >> CC: Len Brown <len.brown@intel.com> >> CC: Christoph Lameter <cl@linux.com> >> Cc: Minchan Kim <minchan.kim@gmail.com> >> CC: Andrew Morton <akpm@linux-foundation.org> >> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >> CC: Wen Congyang <wency@cn.fujitsu.com> >> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> --- >> mm/memory_hotplug.c | 15 +++++++++++---- >> 1 file changed, 11 insertions(+), 4 deletions(-) >> >> Index: linux-3.6/mm/memory_hotplug.c >> =================================================================== >> --- linux-3.6.orig/mm/memory_hotplug.c 2012-10-04 18:29:58.284676075 +0900 >> +++ linux-3.6/mm/memory_hotplug.c 2012-10-04 18:30:03.454680542 +0900 >> @@ -95,10 +95,17 @@ static void release_memory_resource(stru >> static void get_page_bootmem(unsigned long info, struct page *page, >> unsigned long type) >> { >> - page->lru.next = (struct list_head *) type; >> - SetPagePrivate(page); >> - set_page_private(page, info); >> - atomic_inc(&page->_count); >> + unsigned long page_type; >> + >> + page_type = (unsigned long)page->lru.next; > > If I understand correctly, page->lru.next might be uninitialized yet.
Ah yes. I was misunderstanding...
Hi Wen,
When you update the physical hot remove patch-set, please drop the patch.
Thanks, Yasuaki Ishimatsu
> Moreover, I have no seen any good effect in this patch. I don't understand > why we need to increase code complexity. > > > >> + if (page_type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || >> + page_type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){ >> + page->lru.next = (struct list_head *)type; >> + SetPagePrivate(page); >> + set_page_private(page, info); >> + atomic_inc(&page->_count); >> + } else >> + atomic_inc(&page->_count); >> } >> >> /* reference to __meminit __free_pages_bootmem is valid >> >> -- >> 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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