The patch titled Subject: x86,mem-hotplug: pass sync_global_pgds() a correct argument in remove_pagetable() has been added to the -mm tree. Its filename is x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable.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 *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Subject: x86,mem-hotplug: pass sync_global_pgds() a correct argument in remove_pagetable() When hot-adding memory after hot-removing memory, following call traces are shown: kernel BUG at arch/x86/mm/init_64.c:206! ... [<ffffffff815e0c80>] kernel_physical_mapping_init+0x1b2/0x1d2 [<ffffffff815ced94>] init_memory_mapping+0x1d4/0x380 [<ffffffff8104aebd>] arch_add_memory+0x3d/0xd0 [<ffffffff815d03d9>] add_memory+0xb9/0x1b0 [<ffffffff81352415>] acpi_memory_device_add+0x1af/0x28e [<ffffffff81325dc4>] acpi_bus_device_attach+0x8c/0xf0 [<ffffffff813413b9>] acpi_ns_walk_namespace+0xc8/0x17f [<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7 [<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7 [<ffffffff813418ed>] acpi_walk_namespace+0x95/0xc5 [<ffffffff81326b4c>] acpi_bus_scan+0x9a/0xc2 [<ffffffff81326bff>] acpi_scan_bus_device_check+0x8b/0x12e [<ffffffff81326cb5>] acpi_scan_device_check+0x13/0x15 [<ffffffff81320122>] acpi_os_execute_deferred+0x25/0x32 [<ffffffff8107e02b>] process_one_work+0x17b/0x460 [<ffffffff8107edfb>] worker_thread+0x11b/0x400 [<ffffffff8107ece0>] ? rescuer_thread+0x400/0x400 [<ffffffff81085aef>] kthread+0xcf/0xe0 [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140 [<ffffffff815fc76c>] ret_from_fork+0x7c/0xb0 [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140 The patch-sets fix the issue. This patch (of 2): remove_pagetable() gets start argument and passes the argument to sync_global_pgds(). In this case, the argument must not be modified. If the argument is modified and passed to sync_global_pgds(), sync_global_pgds() does not correctly synchronize PGD to PGD entries of all processes MM since synchronized range of memory [start, end] is wrong. Unfortunately the start argument is modified in remove_pagetable(). So this patch fixes the issue. Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx> Cc: Toshi Kani <toshi.kani@xxxxxx> Cc: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/init_64.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff -puN arch/x86/mm/init_64.c~x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable arch/x86/mm/init_64.c --- a/arch/x86/mm/init_64.c~x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable +++ a/arch/x86/mm/init_64.c @@ -975,19 +975,20 @@ static void __meminit remove_pagetable(unsigned long start, unsigned long end, bool direct) { unsigned long next; + unsigned long addr; pgd_t *pgd; pud_t *pud; bool pgd_changed = false; - for (; start < end; start = next) { - next = pgd_addr_end(start, end); + for (addr = start; addr < end; addr = next) { + next = pgd_addr_end(addr, end); - pgd = pgd_offset_k(start); + pgd = pgd_offset_k(addr); if (!pgd_present(*pgd)) continue; pud = (pud_t *)pgd_page_vaddr(*pgd); - remove_pud_table(pud, start, next, direct); + remove_pud_table(pud, addr, next, direct); if (free_pud_table(pud, pgd)) pgd_changed = true; } _ Patches currently in -mm which might be from isimatu.yasuaki@xxxxxxxxxxxxxx are x86mem-hotplug-pass-sync_global_pgds-a-correct-argument-in-remove_pagetable.patch x86mem-hotplug-modify-pgd-entry-when-removing-memory.patch mem-hotplug-avoid-illegal-state-prefixed-with-legal-state-when-changing-state-of-memory_block.patch mem-hotplug-introduce-mmop_offline-to-replace-the-hard-coding-1.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