From: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx> Subject: memory-hotplug: use dev_online for memhp_auto_online Commit 31bc3858e "add automatic onlining policy for the newly added memory" provides the capability to have added memory automatically onlined during add, but this appears to be slightly broken. The current implementation uses walk_memory_range() to call online_memory_block, which uses memory_block_change_state() to online the memory. Instead, we should be calling device_online() for the memory block in online_memory_block(). This would online the memory (the memory bus online routine memory_subsys_online() called from device_online calls memory_block_change_state()) and properly update the device struct offline flag. As a result of the current implementation, attempting to remove a memory block after adding it using auto online fails. This is because doing a remove, for instance 'echo offline > /sys/devices/system/memory/memoryXXX/state', uses device_offline() which checks the dev->offline flag. Link: http://lkml.kernel.org/r/20170222220744.8119.19687.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Michael Roth <mdroth@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/base/memory.c | 2 +- include/linux/memory.h | 3 --- mm/memory_hotplug.c | 2 +- 3 files changed, 2 insertions(+), 5 deletions(-) diff -puN drivers/base/memory.c~memory-hotplug-use-dev_online-for-memhp_auto_online drivers/base/memory.c --- a/drivers/base/memory.c~memory-hotplug-use-dev_online-for-memhp_auto_online +++ a/drivers/base/memory.c @@ -249,7 +249,7 @@ memory_block_action(unsigned long phys_i return ret; } -int memory_block_change_state(struct memory_block *mem, +static int memory_block_change_state(struct memory_block *mem, unsigned long to_state, unsigned long from_state_req) { int ret = 0; diff -puN include/linux/memory.h~memory-hotplug-use-dev_online-for-memhp_auto_online include/linux/memory.h --- a/include/linux/memory.h~memory-hotplug-use-dev_online-for-memhp_auto_online +++ a/include/linux/memory.h @@ -109,9 +109,6 @@ extern void unregister_memory_notifier(s extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); extern int register_new_memory(int, struct mem_section *); -extern int memory_block_change_state(struct memory_block *mem, - unsigned long to_state, - unsigned long from_state_req); #ifdef CONFIG_MEMORY_HOTREMOVE extern int unregister_memory_section(struct mem_section *); #endif diff -puN mm/memory_hotplug.c~memory-hotplug-use-dev_online-for-memhp_auto_online mm/memory_hotplug.c --- a/mm/memory_hotplug.c~memory-hotplug-use-dev_online-for-memhp_auto_online +++ a/mm/memory_hotplug.c @@ -1337,7 +1337,7 @@ int zone_for_memory(int nid, u64 start, static int online_memory_block(struct memory_block *mem, void *arg) { - return memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); + return device_online(&mem->dev); } /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ _ -- 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
