path: root/mm/page_isolation.c
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2008-11-06memory hotplug: fix page_zone() calculation in test_pages_isolated()Gerald Schaefer
My last bugfix here (adding zone->lock) introduced a new problem: Using page_zone(pfn_to_page(pfn)) to get the zone after the for() loop is wrong. pfn will then be >= end_pfn, which may be in a different zone or not present at all. This may lead to an addressing exception in page_zone() or spin_lock_irqsave(). Now I use __first_valid_page() again after the loop to find a valid page for page_zone(). Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: Nathan Fontenot <nfont@austin.ibm.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-02memory hotplug: missing zone->lock in test_pages_isolated()Gerald Schaefer
__test_page_isolated_in_pageblock() in mm/page_isolation.c has a comment saying that the caller must hold zone->lock. But the only caller of that function, test_pages_isolated(), does not hold zone->lock and the lock is also not acquired anywhere before. This patch adds the missing zone->lock to test_pages_isolated(). We reproducibly run into BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test, see trace below. This patch fixes that problem, it would be good if we could have it in 2.6.27. kernel BUG at /home/autobuild/BUILD/linux-2.6.26-20080909/mm/page_alloc.c:4561! illegal operation: 0001 [#1] PREEMPT SMP Modules linked in: dm_multipath sunrpc bonding qeth_l3 dm_mod qeth ccwgroup vmur CPU: 1 Not tainted 2.6.26-29.x.20080909-s390default #1 Process memory_loop_all (pid: 10025, task: 2f444028, ksp: 2b10dd28) Krnl PSW : 040c0000 801727ea (__offline_isolated_pages+0x18e/0x1c4) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 Krnl GPRS: 00000000 7e27fc00 00000000 7e27fc00 00000000 00000400 00014000 7e27fc01 00606f00 7e27fc00 00013fe0 2b10dd28 00000005 80172662 801727b2 2b10dd28 Krnl Code: 801727de: 5810900c l %r1,12(%r9) 801727e2: a7f4ffb3 brc 15,80172748 801727e6: a7f40001 brc 15,801727e8 >801727ea: a7f4ffbc brc 15,80172762 801727ee: a7f40001 brc 15,801727f0 801727f2: a7f4ffaf brc 15,80172750 801727f6: 0707 bcr 0,%r7 801727f8: 0017 unknown Call Trace: ([<0000000000172772>] __offline_isolated_pages+0x116/0x1c4) [<00000000001953a2>] offline_isolated_pages_cb+0x22/0x34 [<000000000013164c>] walk_memory_resource+0xcc/0x11c [<000000000019520e>] offline_pages+0x36a/0x498 [<00000000001004d6>] remove_memory+0x36/0x44 [<000000000028fb06>] memory_block_change_state+0x112/0x150 [<000000000028ffb8>] store_mem_state+0x90/0xe4 [<0000000000289c00>] sysdev_store+0x34/0x40 [<00000000001ee048>] sysfs_write_file+0xd0/0x178 [<000000000019b1a8>] vfs_write+0x74/0x118 [<000000000019b9ae>] sys_write+0x46/0x7c [<000000000011160e>] sysc_do_restart+0x12/0x16 [<0000000077f3e8ca>] 0x77f3e8ca Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02Remove '#include <stddef.h>' from mm/page_isolation.cDavid Woodhouse
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2007-11-14memory hotremove: unset migrate type "ISOLATE" after removalKAMEZAWA Hiroyuki
We should unset migrate type "ISOLATE" when we successfully removed memory. But current code has BUG and cannot works well. This patch also includes bugfix? to change get_pageblock_flags to get_pageblock_migratetype(). Thanks to Badari Pulavarty for finding this. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16memory unplug: page isolationKAMEZAWA Hiroyuki
Implement generic chunk-of-pages isolation method by using page grouping ops. This patch add MIGRATE_ISOLATE to MIGRATE_TYPES. By this - MIGRATE_TYPES increases. - bitmap for migratetype is enlarged. pages of MIGRATE_ISOLATE migratetype will not be allocated even if it is free. By this, you can isolated *freed* pages from users. How-to-free pages is not a purpose of this patch. You may use reclaim and migrate codes to free pages. If start_isolate_page_range(start,end) is called, - migratetype of the range turns to be MIGRATE_ISOLATE if its type is MIGRATE_MOVABLE. (*) this check can be updated if other memory reclaiming works make progress. - MIGRATE_ISOLATE is not on migratetype fallback list. - All free pages and will-be-freed pages are isolated. To check all pages in the range are isolated or not, use test_pages_isolated(), To cancel isolation, use undo_isolate_page_range(). Changes V6 -> V7 - removed unnecessary #ifdef There are HOLES_IN_ZONE handling codes...I'm glad if we can remove them.. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>