Messages in this thread Patches in this message | | | Date | Mon, 1 Feb 2010 20:22:02 +0800 | From | Shaohui Zheng <> | Subject | Re: [Patch - Resend v4] Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel |
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On Mon, Feb 01, 2010 at 12:41:24PM +0800, Wu Fengguang wrote: > Shaohui, > > Some style nitpicks.. > > > #ifdef CONFIG_MEMORY_HOTPLUG > > +/** > > Should use /* here. Agree. > > > + * After memory hotplug, the variable max_pfn, max_low_pfn and high_memory will > > + * be affected, it will be updated in this function. > > + */ > > +static inline void __meminit update_end_of_memory_vars(u64 start, > > The "inline" and "__meminit" are both redundant here. will remove both. > > > + max_low_pfn = max_pfn = end_pfn; > > One assignment per line is preferred. will change to 2 statements. > > Thanks, > Fengguang
Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel
The new added memory can not be access by interface /dev/mem, because we do not update the variables high_memory, max_pfn and max_low_pfn.
Add a function update_end_of_memory_vars to update these variables for 64-bit kernel.
CC: Andi Kleen <ak@linux.intel.com> CC: Li Haicheng <haicheng.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5198b9b..e1c9202 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -49,6 +49,7 @@ #include <asm/numa.h> #include <asm/cacheflush.h> #include <asm/init.h> +#include <linux/bootmem.h> static unsigned long dma_reserve __initdata; @@ -616,6 +617,21 @@ void __init paging_init(void) */ #ifdef CONFIG_MEMORY_HOTPLUG /* + * After memory hotplug, the variables max_pfn, max_low_pfn and high_memory will + * be affected, they will be updated in this function. + */ +static void update_end_of_memory_vars(u64 start, u64 size) +{ + unsigned long end_pfn = PFN_UP(start + size); + + if (end_pfn > max_pfn) { + max_pfn = end_pfn; + max_low_pfn = end_pfn; + high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; + } +} + +/* * Memory is added always to NORMAL zone. This means you will never get * additional DMA/DMA32 memory. */ @@ -634,6 +650,9 @@ int arch_add_memory(int nid, u64 start, u64 size) ret = __add_pages(nid, zone, start_pfn, nr_pages); WARN_ON_ONCE(ret); + /* update max_pfn, max_low_pfn and high_memory */ + update_end_of_memory_vars(start, size); + return ret; } EXPORT_SYMBOL_GPL(arch_add_memory); -- Thanks & Regards, Shaohui Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel
The new added memory can not be access by interface /dev/mem, because we do not update the variables high_memory, max_pfn and max_low_pfn.
Add a function update_end_of_memory_vars to update these variables for 64-bit kernel.
CC: Andi Kleen <ak@linux.intel.com> CC: Li Haicheng <haicheng.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5198b9b..e1c9202 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -49,6 +49,7 @@ #include <asm/numa.h> #include <asm/cacheflush.h> #include <asm/init.h> +#include <linux/bootmem.h> static unsigned long dma_reserve __initdata; @@ -616,6 +617,21 @@ void __init paging_init(void) */ #ifdef CONFIG_MEMORY_HOTPLUG /* + * After memory hotplug, the variables max_pfn, max_low_pfn and high_memory will + * be affected, they will be updated in this function. + */ +static void update_end_of_memory_vars(u64 start, u64 size) +{ + unsigned long end_pfn = PFN_UP(start + size); + + if (end_pfn > max_pfn) { + max_pfn = end_pfn; + max_low_pfn = end_pfn; + high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; + } +} + +/* * Memory is added always to NORMAL zone. This means you will never get * additional DMA/DMA32 memory. */ @@ -634,6 +650,9 @@ int arch_add_memory(int nid, u64 start, u64 size) ret = __add_pages(nid, zone, start_pfn, nr_pages); WARN_ON_ONCE(ret); + /* update max_pfn, max_low_pfn and high_memory */ + update_end_of_memory_vars(start, size); + return ret; } EXPORT_SYMBOL_GPL(arch_add_memory); | |