From e2ff39400d81233374e780b133496a2296643d7d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 8 May 2013 00:29:49 +0200 Subject: ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes During ACPI memory hotplug configuration bind memory blocks residing in modules removable through the standard ACPI mechanism to struct acpi_device objects associated with ACPI namespace objects representing those modules. Accordingly, unbind those memory blocks from the struct acpi_device objects when the memory modules in question are being removed. When "offline" operation for devices representing memory blocks is introduced, this will allow the ACPI core's device hot-remove code to use it to carry out remove_memory() for those memory blocks and check the results of that before it actually removes the modules holding them from the system. Since walk_memory_range() is used for accessing all memory blocks corresponding to a given ACPI namespace object, it is exported from memory_hotplug.c so that the code in acpi_memhotplug.c can use it. Signed-off-by: Rafael J. Wysocki Tested-by: Vasilis Liaskovitis Reviewed-by: Toshi Kani --- mm/memory_hotplug.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a221fac1f47d..5ea1287ee91f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1618,6 +1618,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) { return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); } +#endif /* CONFIG_MEMORY_HOTREMOVE */ /** * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) @@ -1631,7 +1632,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) * * Returns the return value of func. */ -static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, +int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, void *arg, int (*func)(struct memory_block *, void *)) { struct memory_block *mem = NULL; @@ -1668,6 +1669,7 @@ static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, return 0; } +#ifdef CONFIG_MEMORY_HOTREMOVE /** * offline_memory_block_cb - callback function for offlining memory block * @mem: the memory block to be offlined -- cgit v1.2.3 From ea50be59345a2b714fd3ed43e1bba89906c177c3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 May 2013 10:41:50 +0200 Subject: Driver core / MM: Drop offline_memory_block() Since offline_memory_block(mem) is functionally equivalent to device_offline(&mem->dev), make the only caller of the former use the latter instead and drop offline_memory_block() entirely. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Toshi Kani --- mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 5ea1287ee91f..a39841d240e8 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1680,7 +1680,7 @@ int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, static int offline_memory_block_cb(struct memory_block *mem, void *arg) { int *ret = arg; - int error = offline_memory_block(mem); + int error = device_offline(&mem->dev); if (error != 0 && *ret == 0) *ret = error; -- cgit v1.2.3 From 242831eb15a06fa4414eaa705fdc6dd432ab98d1 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 27 May 2013 12:58:46 +0200 Subject: Memory hotplug / ACPI: Simplify memory removal Now that the memory offlining should be taken care of by the companion device offlining code in acpi_scan_hot_remove(), the ACPI memory hotplug driver doesn't need to offline it in remove_memory() any more. Moreover, since the return value of remove_memory() is not used, it's better to make it be a void function and trigger a BUG() if the memory scheduled for removal is not offline. Change the code in accordance with the above observations. Signed-off-by: Rafael J. Wysocki Reviewed-by: Toshi Kani --- mm/memory_hotplug.c | 71 ++++++----------------------------------------------- 1 file changed, 8 insertions(+), 63 deletions(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a39841d240e8..7026fbc42aaa 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1670,24 +1670,6 @@ int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, } #ifdef CONFIG_MEMORY_HOTREMOVE -/** - * offline_memory_block_cb - callback function for offlining memory block - * @mem: the memory block to be offlined - * @arg: buffer to hold error msg - * - * Always return 0, and put the error msg in arg if any. - */ -static int offline_memory_block_cb(struct memory_block *mem, void *arg) -{ - int *ret = arg; - int error = device_offline(&mem->dev); - - if (error != 0 && *ret == 0) - *ret = error; - - return 0; -} - static int is_memblock_offlined_cb(struct memory_block *mem, void *arg) { int ret = !is_memblock_offlined(mem); @@ -1813,54 +1795,22 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); -int __ref remove_memory(int nid, u64 start, u64 size) +void __ref remove_memory(int nid, u64 start, u64 size) { - unsigned long start_pfn, end_pfn; - int ret = 0; - int retry = 1; - - start_pfn = PFN_DOWN(start); - end_pfn = PFN_UP(start + size - 1); - - /* - * When CONFIG_MEMCG is on, one memory block may be used by other - * blocks to store page cgroup when onlining pages. But we don't know - * in what order pages are onlined. So we iterate twice to offline - * memory: - * 1st iterate: offline every non primary memory block. - * 2nd iterate: offline primary (i.e. first added) memory block. - */ -repeat: - walk_memory_range(start_pfn, end_pfn, &ret, - offline_memory_block_cb); - if (ret) { - if (!retry) - return ret; - - retry = 0; - ret = 0; - goto repeat; - } + int ret; lock_memory_hotplug(); /* - * we have offlined all memory blocks like this: - * 1. lock memory hotplug - * 2. offline a memory block - * 3. unlock memory hotplug - * - * repeat step1-3 to offline the memory block. All memory blocks - * must be offlined before removing memory. But we don't hold the - * lock in the whole operation. So we should check whether all - * memory blocks are offlined. + * All memory blocks must be offlined before removing memory. Check + * whether all memory blocks in question are offline and trigger a BUG() + * if this is not the case. */ - - ret = walk_memory_range(start_pfn, end_pfn, NULL, + ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, is_memblock_offlined_cb); if (ret) { unlock_memory_hotplug(); - return ret; + BUG(); } /* remove memmap entry */ @@ -1871,17 +1821,12 @@ repeat: try_offline_node(nid); unlock_memory_hotplug(); - - return 0; } #else int offline_pages(unsigned long start_pfn, unsigned long nr_pages) { return -EINVAL; } -int remove_memory(int nid, u64 start, u64 size) -{ - return -EINVAL; -} +void remove_memory(int nid, u64 start, u64 size) {} #endif /* CONFIG_MEMORY_HOTREMOVE */ EXPORT_SYMBOL_GPL(remove_memory); -- cgit v1.2.3 From aba6efc47133af4941cda16e690f71b7ad894da2 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 1 Jun 2013 22:24:07 +0200 Subject: Memory hotplug: Move alternative function definitions to header Move the definitions of offline_pages() and remove_memory() for CONFIG_MEMORY_HOTREMOVE to memory_hotplug.h, where they belong, and make them static inline. Signed-off-by: Rafael J. Wysocki --- mm/memory_hotplug.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7026fbc42aaa..490e3d401e2c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1822,11 +1822,5 @@ void __ref remove_memory(int nid, u64 start, u64 size) unlock_memory_hotplug(); } -#else -int offline_pages(unsigned long start_pfn, unsigned long nr_pages) -{ - return -EINVAL; -} -void remove_memory(int nid, u64 start, u64 size) {} -#endif /* CONFIG_MEMORY_HOTREMOVE */ EXPORT_SYMBOL_GPL(remove_memory); +#endif /* CONFIG_MEMORY_HOTREMOVE */ -- cgit v1.2.3