From 68c3a6ac65f675b4b783635787fa0ed896f5b3d5 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 6 Apr 2020 20:06:40 -0700 Subject: drivers/base/memory.c: drop section_count Patch series "mm: drop superfluous section checks when onlining/offlining". Let's drop some superfluous section checks on the onlining/offlining path. This patch (of 3): Since commit c5e79ef561b0 ("mm/memory_hotplug.c: don't allow to online/offline memory blocks with holes") we have a generic check in offline_pages() that disallows offlining memory blocks with holes. Memory blocks with missing sections are just another variant of these type of blocks. We can stop checking (and especially storing) present sections. A proper error message is now printed why offlining failed. section_count was initially introduced in commit 07681215975e ("Driver core: Add section count to memory_block struct") in order to detect when it is okay to remove a memory block. It was used in commit 26bbe7ef6d5c ("drivers/base/memory.c: prohibit offlining of memory blocks with missing sections") to disallow offlining memory blocks with missing sections. As we refactored creation/removal of memory devices and have a proper check for holes in place, we can drop the section_count. This also removes a leftover comment regarding the mem_sysfs_mutex, which was removed in commit 848e19ad3c33 ("drivers/base/memory.c: drop the mem_sysfs_mutex"). Signed-off-by: David Hildenbrand Signed-off-by: Andrew Morton Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Michal Hocko Cc: Dan Williams Cc: Pavel Tatashin Cc: Anshuman Khandual Link: http://lkml.kernel.org/r/20200127110424.5757-2-david@redhat.com Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'drivers/base/memory.c') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 4086718f6876..086997212dbb 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -267,10 +267,6 @@ static int memory_subsys_offline(struct device *dev) if (mem->state == MEM_OFFLINE) return 0; - /* Can't offline block with non-present sections */ - if (mem->section_count != sections_per_block) - return -EINVAL; - return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); } @@ -627,7 +623,7 @@ static int init_memory_block(struct memory_block **memory, static int add_memory_block(unsigned long base_section_nr) { - int ret, section_count = 0; + int section_count = 0; struct memory_block *mem; unsigned long nr; @@ -638,12 +634,8 @@ static int add_memory_block(unsigned long base_section_nr) if (section_count == 0) return 0; - ret = init_memory_block(&mem, base_memory_block_id(base_section_nr), - MEM_ONLINE); - if (ret) - return ret; - mem->section_count = section_count; - return 0; + return init_memory_block(&mem, base_memory_block_id(base_section_nr), + MEM_ONLINE); } static void unregister_memory(struct memory_block *memory) @@ -679,7 +671,6 @@ int create_memory_block_devices(unsigned long start, unsigned long size) ret = init_memory_block(&mem, block_id, MEM_OFFLINE); if (ret) break; - mem->section_count = sections_per_block; } if (ret) { end_block_id = block_id; @@ -688,7 +679,6 @@ int create_memory_block_devices(unsigned long start, unsigned long size) mem = find_memory_block_by_id(block_id); if (WARN_ON_ONCE(!mem)) continue; - mem->section_count = 0; unregister_memory(mem); } } @@ -717,7 +707,6 @@ void remove_memory_block_devices(unsigned long start, unsigned long size) mem = find_memory_block_by_id(block_id); if (WARN_ON_ONCE(!mem)) continue; - mem->section_count = 0; unregister_memory_block_under_nodes(mem); unregister_memory(mem); } -- cgit