The patch titled mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset has been added to the -mm tree. Its filename is mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset From: Haicheng Li <haicheng.li@xxxxxxxxxxxxxxx> 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: [ 47.326005] ------------[ cut here ]------------ [ 47.328431] kernel BUG at mm/page_alloc.c:1239! [ 47.333208] invalid opcode: 0000 [#1] SMP [ 47.333208] last sysfs file: /sys/devices/system/cpu/probe [ 47.333208] CPU 0 [ 47.333208] Modules linked in: snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq snd_timer snd_seq_device snd soundcore snd_page_alloc drm [ 47.333208] Pid: 2379, comm: cp Not tainted 2.6.32 #4 Bochs [ 47.333208] RIP: 0010:[<ffffffff8112ff13>] [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900 [ 47.333208] RSP: 0018:ffff88000d1e78a8 EFLAGS: 00010202 [ 47.333208] RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000004 [ 47.333208] RDX: 000000000001037d RSI: ffffea0000696ac8 RDI: ffff88000d9e8e80 [ 47.333208] RBP: ffff88000d1e79c8 R08: 0000000000030000 R09: 0000000000000001 [ 47.333208] R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff82610700 [ 47.333208] R13: ffffea0000696ac8 R14: ffff88000d9e8e80 R15: 00000000000000fd [ 47.333208] FS: 00007f9fb1279790(0000) GS:ffff880003400000(0000) knlGS:0000000000000000 [ 47.333208] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 47.333208] CR2: 00007f9fb128940a CR3: 000000000d98a000 CR4: 00000000000006f0 [ 47.333208] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 47.333208] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 47.333208] Process cp (pid: 2379, threadinfo ffff88000d1e6000, task ffff88000d3e0000) [ 47.333208] Stack: [ 47.333208] 0000000000000000 ffffea0000697068 ffffea0000697010 ffff88000d3e1288 [ 47.333208] <0> 0000000100000001 ffffffff82610700 0000000000000009 00000040ffffffff [ 47.333208] <0> ffff88000d3e1288 ffff880000009d08 ffff88000d9e8f10 000000038105fe6f [ 47.333208] Call Trace: [ 47.333208] [<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0 [ 47.333208] [<ffffffff8113257d>] ? __do_page_cache_readahead+0xad/0x260 [ 47.333208] [<ffffffff8105f171>] ? kvm_clock_read+0x21/0x30 [ 47.333208] [<ffffffff81043189>] ? sched_clock+0x9/0x10 [ 47.333208] [<ffffffff810b3135>] ? sched_clock_local+0x25/0x90 [ 47.333208] [<ffffffff810b3258>] ? sched_clock_cpu+0xb8/0x110 [ 47.333208] [<ffffffff81162e67>] alloc_pages_current+0x87/0xd0 [ 47.333208] [<ffffffff81128407>] __page_cache_alloc+0x67/0x70 [ 47.333208] [<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260 [ 47.333208] [<ffffffff8113257d>] ? __do_page_cache_readahead+0xad/0x260 [ 47.333208] [<ffffffff81127f04>] ? find_get_page+0xb4/0x120 [ 47.333208] [<ffffffff81132751>] ra_submit+0x21/0x30 [ 47.333208] [<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0 [ 47.333208] [<ffffffff810bf59d>] ? lock_release_holdtime+0x3d/0x170 [ 47.333208] [<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0 [ 47.333208] [<ffffffff81127e50>] ? find_get_page+0x0/0x120 [ 47.333208] [<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670 [ 47.333208] [<ffffffff81266cfa>] nfs_file_read+0xca/0x130 [ 47.333208] [<ffffffff813bd12b>] ? __up_read+0x8b/0xb0 [ 47.333208] [<ffffffff8117b20a>] do_sync_read+0xfa/0x140 [ 47.333208] [<ffffffff8103cad0>] ? restore_args+0x0/0x30 [ 47.333208] [<ffffffff810acc60>] ? autoremove_wake_function+0x0/0x40 [ 47.333208] [<ffffffff816bcece>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 47.333208] [<ffffffff8117bf75>] vfs_read+0xb5/0x1a0 [ 47.333208] [<ffffffff8117c151>] sys_read+0x51/0x80 [ 47.333208] [<ffffffff8103c032>] system_call_fastpath+0x16/0x1b [ 47.333208] Code: 49 89 c5 8b 95 18 ff ff ff 4c 89 f7 e8 27 1d 01 00 48 8b bd 30 ff ff ff e8 1b d5 58 00 4d 85 ed 0f 85 25 fa ff ff e9 31 fe ff ff <0f> 0b eb fe 83 7d ac 01 7e ab 83 3d b8 05 4e 01 00 75 a2 be c8 [ 47.333208] RIP [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900 [ 47.333208] RSP <ffff88000d1e78a8> [ 47.468914] ---[ end trace 4bda28328b9990db ] Signed-off-by: Haicheng Li <haicheng.li@xxxxxxxxxxxxxxx> Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> Reviewed-by: Andi Kleen <andi.kleen@xxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Cc: Mel Gorman <mel@xxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mmzone.h | 2 +- init/main.c | 2 +- mm/memory_hotplug.c | 18 +++++++++++++----- mm/page_alloc.c | 17 +++++++++++++---- 4 files changed, 28 insertions(+), 11 deletions(-) diff -puN include/linux/mmzone.h~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset include/linux/mmzone.h --- a/include/linux/mmzone.h~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset +++ a/include/linux/mmzone.h @@ -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); diff -puN init/main.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset init/main.c --- a/init/main.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset +++ a/init/main.c @@ -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); diff -puN mm/memory_hotplug.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset mm/memory_hotplug.c --- a/mm/memory_hotplug.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset +++ a/mm/memory_hotplug.c @@ -389,6 +389,11 @@ int online_pages(unsigned long pfn, unsi 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, unsi * 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, unsi 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, unsi 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(); diff -puN mm/page_alloc.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset mm/page_alloc.c --- a/mm/page_alloc.c~mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset +++ a/mm/page_alloc.c @@ -2572,7 +2572,7 @@ int numa_zonelist_order_handler(ctl_tabl 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 */ 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 *d 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 *d 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(); _ Patches currently in -mm which might be from haicheng.li@xxxxxxxxxxxxxxx are mem-hotplug-separate-setup_per_cpu_pageset-into-separate-functions.patch mem-hotplug-avoid-multiple-zones-sharing-same-boot-strapping-boot_pageset.patch mem-hotplug-fix-potential-race-while-building-zonelist-for-new-populated-zone.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html