From 56c6b5d3acd8e0cfc302ff56f58c15fea27064de Mon Sep 17 00:00:00 2001 From: Seth Jennings Date: Thu, 14 Jan 2016 15:20:21 -0800 Subject: drivers/base/memory.c: clean up section counting Right now, section_count is calculated in add_memory_block(). However, init_memory_block() increments section_count as well, which, at first, seems like it would lead to an off-by-one error. There is no harm done because add_memory_block() immediately overwrites the mem->section_count, but it is messy. This commit moves the increment out of the common init_memory_block() (called by both add_memory_block() and register_new_memory()) and adds it to register_new_memory(). Signed-off-by: Seth Jennings Cc: Andrew Banman Cc: Daniel J Blueman Cc: Yinghai Lu Cc: Greg KH Cc: Russ Anderson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 25425d3f2575..17173f655f89 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -618,7 +618,6 @@ static int init_memory_block(struct memory_block **memory, base_memory_block_id(scn_nr) * sections_per_block; mem->end_section_nr = mem->start_section_nr + sections_per_block - 1; mem->state = state; - mem->section_count++; start_pfn = section_nr_to_pfn(mem->start_section_nr); mem->phys_device = arch_get_memory_phys_device(start_pfn); @@ -672,6 +671,7 @@ int register_new_memory(int nid, struct mem_section *section) ret = init_memory_block(&mem, section, MEM_OFFLINE); if (ret) goto out; + mem->section_count++; } if (mem->section_count == sections_per_block) -- cgit v1.2.3 From cc292b0b43027cce9310a18ec3239b5e9b4ea301 Mon Sep 17 00:00:00 2001 From: Seth Jennings Date: Thu, 14 Jan 2016 15:20:24 -0800 Subject: drivers/base/memory.c: rename remove_memory_block() to remove_memory_section() The function removes a section, not a block. Rename to reflect actual functionality. Signed-off-by: Seth Jennings Cc: Andrew Banman Cc: Daniel J Blueman Cc: Yinghai Lu Cc: Greg KH Cc: Russ Anderson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 17173f655f89..6d7b14c2798e 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -692,7 +692,7 @@ unregister_memory(struct memory_block *memory) device_unregister(&memory->dev); } -static int remove_memory_block(unsigned long node_id, +static int remove_memory_section(unsigned long node_id, struct mem_section *section, int phys_device) { struct memory_block *mem; @@ -716,7 +716,7 @@ int unregister_memory_section(struct mem_section *section) if (!present_section(section)) return -EINVAL; - return remove_memory_block(0, section, 0); + return remove_memory_section(0, section, 0); } #endif /* CONFIG_MEMORY_HOTREMOVE */ -- cgit v1.2.3 From cb5490a5eea415106d7438df440da5fb1e17318d Mon Sep 17 00:00:00 2001 From: John Allen Date: Thu, 14 Jan 2016 15:22:16 -0800 Subject: drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64 Fix a bug where a kernel warning is triggered when performing a memory hotplug on ppc64. This warning may also occur on any architecture that uses the memory_probe_store interface. WARNING: at drivers/base/memory.c:200 CPU: 9 PID: 13042 Comm: systemd-udevd Not tainted 4.4.0-rc4-00113-g0bd0f1e-dirty #7 NIP [c00000000055e034] pages_correctly_reserved+0x134/0x1b0 LR [c00000000055e7f8] memory_subsys_online+0x68/0x140 Call Trace: memory_subsys_online+0x68/0x140 device_online+0xb4/0x120 store_mem_state+0xb0/0x180 dev_attr_store+0x34/0x60 sysfs_kf_write+0x64/0xa0 kernfs_fop_write+0x17c/0x1e0 __vfs_write+0x40/0x160 vfs_write+0xb8/0x200 SyS_write+0x60/0x110 system_call+0x38/0xd0 The warning is triggered because there is a udev rule that automatically tries to online memory after it has been added. The udev rule varies from distro to distro, but will generally look something like: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" On any architecture that uses memory_probe_store to reserve memory, the udev rule will be triggered after the first section of the block is reserved and will subsequently attempt to online the entire block, interrupting the memory reservation process and causing the warning. This patch modifies memory_probe_store to add a block of memory with a single call to add_memory as opposed to looping through and adding each section individually. A single call to add_memory is protected by the mem_hotplug mutex which will prevent the udev rule from onlining memory until the reservation of the entire block is complete. Signed-off-by: John Allen Acked-by: Dave Hansen Cc: Nathan Fontenot Cc: Michael Ellerman Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 6d7b14c2798e..619fe584a44c 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -450,8 +450,7 @@ memory_probe_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { u64 phys_addr; - int nid; - int i, ret; + int nid, ret; unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block; ret = kstrtoull(buf, 0, &phys_addr); @@ -461,15 +460,12 @@ memory_probe_store(struct device *dev, struct device_attribute *attr, if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1)) return -EINVAL; - for (i = 0; i < sections_per_block; i++) { - nid = memory_add_physaddr_to_nid(phys_addr); - ret = add_memory(nid, phys_addr, - PAGES_PER_SECTION << PAGE_SHIFT); - if (ret) - goto out; + nid = memory_add_physaddr_to_nid(phys_addr); + ret = add_memory(nid, phys_addr, + MIN_MEMORY_BLOCK_SIZE * sections_per_block); - phys_addr += MIN_MEMORY_BLOCK_SIZE; - } + if (ret) + goto out; ret = count; out: -- cgit v1.2.3