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Commit 1f522509 authored by Haicheng Li's avatar Haicheng Li Committed by Linus Torvalds
Browse files

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:
   [<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0
   [<ffffffff81162e67>] alloc_pages_current+0x87/0xd0
   [<ffffffff81128407>] __page_cache_alloc+0x67/0x70
   [<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260
   [<ffffffff81132751>] ra_submit+0x21/0x30
   [<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0
   [<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0
   [<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670
   [<ffffffff81266cfa>] nfs_file_read+0xca/0x130
   [<ffffffff8117b20a>] do_sync_read+0xfa/0x140
   [<ffffffff8117bf75>] vfs_read+0xb5/0x1a0
   [<ffffffff8117c151>] sys_read+0x51/0x80
   [<ffffffff8103c032>] system_call_fastpath+0x16/0x1b
  RIP  [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900
   RSP <ffff88000d1e78a8>
  ---[ end trace 4bda28328b9990db ]

[akpm@linux-foundation.org: merge fix]
Signed-off-by: default avatarHaicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Reviewed-by: default avatarAndi Kleen <andi.kleen@intel.com>
Reviewed-by: default avatarChristoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 319774e2

include/linux/mmzone.h

+1 −1
Original line number Diff line number Diff line
@@ -652,7 +652,7 @@ typedef struct pglist_data { 


void get_zone_counts(unsigned long *active, unsigned long *inactive,

			unsigned long *free);

void build_all_zonelists(void);

void build_all_zonelists(void *data);

void wakeup_kswapd(struct zone *zone, int order);

int zone_watermark_ok(struct zone *z, int order, unsigned long mark,

		int classzone_idx, int alloc_flags);

init/main.c

+1 −1
Original line number Diff line number Diff line
@@ -567,7 +567,7 @@ asmlinkage void __init start_kernel(void) 
	setup_per_cpu_areas();

	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */



	build_all_zonelists();

	build_all_zonelists(NULL);

	page_alloc_init();



	printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);

kernel/cpu.c

+1 −1
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ int __cpuinit cpu_up(unsigned int cpu) 
	}



	if (pgdat->node_zonelists->_zonerefs->zone == NULL)

		build_all_zonelists();

		build_all_zonelists(NULL);

#endif



	cpu_maps_update_begin();

mm/memory_hotplug.c

+13 −5
Original line number Diff line number Diff line
@@ -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);



	mutex_unlock(&zone_pageset_mutex);

	setup_per_zone_wmarks();

	calculate_zone_inactive_ratio(zone);

	if (onlined_pages) {
@@ -438,9 +449,6 @@ 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();



	writeback_set_ratelimit();

mm/page_alloc.c

+13 −4
Original line number Diff line number Diff line
@@ -2572,7 +2572,7 @@ int numa_zonelist_order_handler(ctl_table *table, int write, 
				NUMA_ZONELIST_ORDER_LEN);

			user_zonelist_order = oldval;

		} else if (oldval != user_zonelist_order)

			build_all_zonelists();

			build_all_zonelists(NULL);

	}

out:

	mutex_unlock(&zl_order_mutex);
@@ -2922,9 +2922,10 @@ static void build_zonelist_cache(pg_data_t *pgdat) 
 */

static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);

static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);

static void setup_zone_pageset(struct zone *zone);



/* return values int ....just for stop_machine() */

static int __build_all_zonelists(void *dummy)

static __init_refok int __build_all_zonelists(void *data)

{

	int nid;

	int cpu;
@@ -2939,6 +2940,14 @@ static int __build_all_zonelists(void *dummy) 
		build_zonelist_cache(pgdat);

	}



#ifdef CONFIG_MEMORY_HOTPLUG

	/* Setup real pagesets for the new zone */

	if (data) {

		struct zone *zone = data;

		setup_zone_pageset(zone);

	}

#endif



	/*

	 * Initialize the boot_pagesets that are going to be used

	 * for bootstrapping processors. The real pagesets for
@@ -2958,7 +2967,7 @@ static int __build_all_zonelists(void *dummy) 
	return 0;

}



void build_all_zonelists(void)

void build_all_zonelists(void *data)

{

	set_zonelist_order();
@@ -2969,7 +2978,7 @@ void build_all_zonelists(void) 
	} else {

		/* we have to stop all cpus to guarantee there is no user

		   of zonelist */

		stop_machine(__build_all_zonelists, NULL, NULL);

		stop_machine(__build_all_zonelists, data, NULL);

		/* cpuset refresh routine should be here */

	}

	vm_total_pages = nr_free_pagecache_pages();