From 1f522509c77a5dea8dc384b735314f03908a6415 Mon Sep 17 00:00:00 2001 From: Haicheng Li Date: Mon, 24 May 2010 14:32:51 -0700 Subject: mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset For each new populated zone of hotadded node, need to update its pagesets with dynamically allocated per_cpu_pageset struct for all possible CPUs: 1) Detach zone->pageset from the shared boot_pageset at end of __build_all_zonelists(). 2) Use mutex to protect zone->pageset when it's still shared in onlined_pages() Otherwises, multiple zones of different nodes would share same boot strapping boot_pageset for same CPU, which will finally cause below kernel panic: ------------[ cut here ]------------ kernel BUG at mm/page_alloc.c:1239! invalid opcode: 0000 [#1] SMP ... Call Trace: [] __alloc_pages_nodemask+0x131/0x7b0 [] alloc_pages_current+0x87/0xd0 [] __page_cache_alloc+0x67/0x70 [] __do_page_cache_readahead+0x120/0x260 [] ra_submit+0x21/0x30 [] ondemand_readahead+0x166/0x2c0 [] page_cache_async_readahead+0x80/0xa0 [] generic_file_aio_read+0x364/0x670 [] nfs_file_read+0xca/0x130 [] do_sync_read+0xfa/0x140 [] vfs_read+0xb5/0x1a0 [] sys_read+0x51/0x80 [] system_call_fastpath+0x16/0x1b RIP [] get_page_from_freelist+0x883/0x900 RSP ---[ end trace 4bda28328b9990db ] [akpm@linux-foundation.org: merge fix] Signed-off-by: Haicheng Li Signed-off-by: Wu Fengguang Reviewed-by: Andi Kleen Reviewed-by: Christoph Lameter Cc: Mel Gorman Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'mm/memory_hotplug.c') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 85eb4d342ac5..089cc97aed3c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -389,6 +389,11 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) int nid; int ret; struct memory_notify arg; + /* + * mutex to protect zone->pageset when it's still shared + * in onlined_pages() + */ + static DEFINE_MUTEX(zone_pageset_mutex); arg.start_pfn = pfn; arg.nr_pages = nr_pages; @@ -415,12 +420,14 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) * This means the page allocator ignores this zone. * So, zonelist must be updated after online. */ + mutex_lock(&zone_pageset_mutex); if (!populated_zone(zone)) need_zonelists_rebuild = 1; ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, online_pages_range); if (ret) { + mutex_unlock(&zone_pageset_mutex); printk(KERN_DEBUG "online_pages %lx at %lx failed\n", nr_pages, pfn); memory_notify(MEM_CANCEL_ONLINE, &arg); @@ -429,8 +436,12 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) zone->present_pages += onlined_pages; zone->zone_pgdat->node_present_pages += onlined_pages; + if (need_zonelists_rebuild) + build_all_zonelists(zone); + else + zone_pcp_update(zone); - zone_pcp_update(zone); + mutex_unlock(&zone_pageset_mutex); setup_per_zone_wmarks(); calculate_zone_inactive_ratio(zone); if (onlined_pages) { @@ -438,10 +449,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); } - if (need_zonelists_rebuild) - build_all_zonelists(); - else - vm_total_pages = nr_free_pagecache_pages(); + vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); -- cgit v1.2.3-55-g7522