Messages in this thread Patch in this message | | | Date | Fri, 28 Mar 2008 17:00:05 -0700 | From | Jeremy Fitzhardinge <> | Subject | [PATCH RFC] hotplug-memory: refactor online_pages to separate zone growth from page onlining |
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The Xen balloon driver needs to separate the process of hot-installing memory into two phases: one to allocate the page structures and configure the zones, and another to actually online the pages of newly installed memory.
This patch splits up the innards of online_pages() into two pieces which correspond to these two phases. The behaviour of online_pages() itself is unchanged.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> --- include/linux/memory_hotplug.h | 3 + mm/memory_hotplug.c | 66 ++++++++++++++++++++++++++++++++-------- 2 files changed, 57 insertions(+), 12 deletions(-)
=================================================================== --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -57,7 +57,10 @@ /* need some defines for these for archs that don't support it */ extern void online_page(struct page *page); /* VM interface that may be used by firmware interface */ +extern int prepare_online_pages(unsigned long pfn, unsigned long nr_pages); +extern unsigned long mark_pages_onlined(unsigned long pfn, unsigned long nr_pages); extern int online_pages(unsigned long, unsigned long); + extern void __offline_isolated_pages(unsigned long, unsigned long); extern int offline_pages(unsigned long, unsigned long, unsigned long); =================================================================== --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -180,31 +180,35 @@ return 0; } - -int online_pages(unsigned long pfn, unsigned long nr_pages) +/* Tell anyone who's interested that we're onlining some memory */ +static int notify_going_online(unsigned long pfn, unsigned long nr_pages) { - unsigned long flags; - unsigned long onlined_pages = 0; - struct zone *zone; - int need_zonelists_rebuild = 0; + struct memory_notify arg; int nid; int ret; - struct memory_notify arg; arg.start_pfn = pfn; arg.nr_pages = nr_pages; arg.status_change_nid = -1; - + nid = page_to_nid(pfn_to_page(pfn)); if (node_present_pages(nid) == 0) arg.status_change_nid = nid; ret = memory_notify(MEM_GOING_ONLINE, &arg); ret = notifier_to_errno(ret); - if (ret) { + if (ret) memory_notify(MEM_CANCEL_ONLINE, &arg); - return ret; - } + + return ret; +} + +/* Grow the zone to fit the expected amount of memory being added */ +static struct zone *online_pages_zone(unsigned long pfn, unsigned long nr_pages) +{ + struct zone *zone; + unsigned long flags; + /* * This doesn't need a lock to do pfn_to_page(). * The section can't be removed here because of the @@ -215,6 +219,16 @@ grow_zone_span(zone, pfn, pfn + nr_pages); grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); pgdat_resize_unlock(zone->zone_pgdat, &flags); + + return zone; +} + +/* Mark a set of pages as online */ +unsigned long mark_pages_onlined(unsigned long pfn, unsigned long nr_pages) +{ + struct zone *zone = page_zone(pfn_to_page(pfn)); + unsigned long onlined_pages = 0; + int need_zonelists_rebuild = 0; /* * If this zone is not populated, then it is not in zonelist. @@ -240,10 +254,38 @@ vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); - if (onlined_pages) + if (onlined_pages) { + struct memory_notify arg; + + arg.start_pfn = pfn; /* ? */ + arg.nr_pages = onlined_pages; + arg.status_change_nid = -1; /* ? */ + memory_notify(MEM_ONLINE, &arg); + } + return onlined_pages; +} + +int prepare_online_pages(unsigned long pfn, unsigned long nr_pages) +{ + int ret = notify_going_online(pfn, nr_pages); + if (ret) + return ret; + + online_pages_zone(pfn, nr_pages); return 0; +} + +int online_pages(unsigned long pfn, unsigned long nr_pages) +{ + int ret; + + ret = prepare_online_pages(pfn, nr_pages); + if (ret == 0) + mark_pages_onlined(pfn, nr_pages); + + return ret; } #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
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