| Message ID | 4FF6ADD9.7040600@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Wen, 2012/07/06 18:20, Wen Congyang wrote: > At 07/06/2012 04:27 PM, Yasuaki Ishimatsu Wrote: >> Hi Wen, >> >> 2012/07/04 19:01, Wen Congyang wrote: >>> At 07/04/2012 01:52 PM, Yasuaki Ishimatsu Wrote: >>>> Hi Wen, >>>> >>>> 2012/07/04 14:08, Wen Congyang wrote: >>>>> At 07/04/2012 12:45 PM, Yasuaki Ishimatsu Wrote: >>>>>> Hi Wen, >>>>>> >>>>>> 2012/07/03 15:35, Wen Congyang wrote: >>>>>>> At 07/03/2012 01:56 PM, Yasuaki Ishimatsu Wrote: >>>>>>>> When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} >>>>>>>> sysfs files are created. But there is no code to remove these files. The patch >>>>>>>> implements the function to remove them. >>>>>>>> >>>>>>>> Note : The code does not free firmware_map_entry since there is no way to free >>>>>>>> memory which is allocated by bootmem. >>>>>>>> >>>>>>>> CC: David Rientjes <rientjes@google.com> >>>>>>>> CC: Jiang Liu <liuj97@gmail.com> >>>>>>>> CC: Len Brown <len.brown@intel.com> >>>>>>>> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> >>>>>>>> CC: Paul Mackerras <paulus@samba.org> >>>>>>>> CC: Christoph Lameter <cl@linux.com> >>>>>>>> Cc: Minchan Kim <minchan.kim@gmail.com> >>>>>>>> CC: Andrew Morton <akpm@linux-foundation.org> >>>>>>>> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >>>>>>>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >>>>>>>> >>>>>>>> --- >>>>>>>> drivers/firmware/memmap.c | 70 +++++++++++++++++++++++++++++++++++++++++++ >>>>>>>> include/linux/firmware-map.h | 6 +++ >>>>>>>> mm/memory_hotplug.c | 6 +++ >>>>>>>> 3 files changed, 81 insertions(+), 1 deletion(-) >>>>>>>> >>>>>>>> Index: linux-3.5-rc4/mm/memory_hotplug.c >>>>>>>> =================================================================== >>>>>>>> --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-07-03 14:22:00.190240794 +0900 >>>>>>>> +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-07-03 14:22:03.549198802 +0900 >>>>>>>> @@ -661,7 +661,11 @@ EXPORT_SYMBOL_GPL(add_memory); >>>>>>>> >>>>>>>> int remove_memory(int nid, u64 start, u64 size) >>>>>>>> { >>>>>>>> - return -EBUSY; >>>>>>>> + lock_memory_hotplug(); >>>>>>>> + /* remove memmap entry */ >>>>>>>> + firmware_map_remove(start, start + size - 1, "System RAM"); >>>>>>>> + unlock_memory_hotplug(); >>>>>>>> + return 0; >>>>>>>> >>>>>>>> } >>>>>>>> EXPORT_SYMBOL_GPL(remove_memory); >>>>>>>> Index: linux-3.5-rc4/include/linux/firmware-map.h >>>>>>>> =================================================================== >>>>>>>> --- linux-3.5-rc4.orig/include/linux/firmware-map.h 2012-07-03 14:21:45.766421116 +0900 >>>>>>>> +++ linux-3.5-rc4/include/linux/firmware-map.h 2012-07-03 14:22:03.550198789 +0900 >>>>>>>> @@ -25,6 +25,7 @@ >>>>>>>> >>>>>>>> int firmware_map_add_early(u64 start, u64 end, const char *type); >>>>>>>> int firmware_map_add_hotplug(u64 start, u64 end, const char *type); >>>>>>>> +int firmware_map_remove(u64 start, u64 end, const char *type); >>>>>>>> >>>>>>>> #else /* CONFIG_FIRMWARE_MEMMAP */ >>>>>>>> >>>>>>>> @@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl >>>>>>>> return 0; >>>>>>>> } >>>>>>>> >>>>>>>> +static inline int firmware_map_remove(u64 start, u64 end, const char *type) >>>>>>>> +{ >>>>>>>> + return 0; >>>>>>>> +} >>>>>>>> + >>>>>>>> #endif /* CONFIG_FIRMWARE_MEMMAP */ >>>>>>>> >>>>>>>> #endif /* _LINUX_FIRMWARE_MAP_H */ >>>>>>>> Index: linux-3.5-rc4/drivers/firmware/memmap.c >>>>>>>> =================================================================== >>>>>>>> --- linux-3.5-rc4.orig/drivers/firmware/memmap.c 2012-07-03 14:21:45.761421180 +0900 >>>>>>>> +++ linux-3.5-rc4/drivers/firmware/memmap.c 2012-07-03 14:22:03.569198549 +0900 >>>>>>>> @@ -79,7 +79,16 @@ static const struct sysfs_ops memmap_att >>>>>>>> .show = memmap_attr_show, >>>>>>>> }; >>>>>>>> >>>>>>>> +static void release_firmware_map_entry(struct kobject *kobj) >>>>>>>> +{ >>>>>>>> + /* >>>>>>>> + * FIXME : There is no idea. >>>>>>>> + * How to free the entry which allocated bootmem? >>>>>>>> + */ >>>>>>> >>>>>>> I find a function free_bootmem(), but I am not sure whether it can work here. >>>>>> >>>>>> It cannot work here. >>>>>> >>>>>>> Another problem: how to check whether the entry uses bootmem? >>>>>> >>>>>> When firmware_map_entry is allocated by kzalloc(), the page has PG_slab. >>>>> >>>>> This is not true. In my test, I find the page does not have PG_slab sometimes. >>>> >>>> I think that it depends on the allocated size. firmware_map_entry size is >>>> smaller than PAGE_SIZE. So the page has PG_Slab. >>> >>> In my test, I add printk in the function firmware_map_add_hotplug() to display >>> page's flags. And sometimes the page is not allocated by slab(I use PageSlab() >>> to verify it). >> >> How did you check it? Could you send your debug patch? > > When the memory is not allocated from slab, the flags is 0x10000000008000. Thank you for sending the patch. I think the page to not have PageSlab is a compound page. So we can check whether the entry is allocate from bootmem or not as follow: static void release_firmware_map_entry(struct kobject *kobj) { struct firmware_map_entry *entry = to_memmap_entry(kobj); struct page *head_page; head_page = virt_to_head_page(entry); if (PageSlab(head_page)) kfree(etnry); else /* the entry is allocated from bootmem */ } Thanks, Yasuaki Ishimatsu > > From 8dd51368d6c03edf7edc89cab17441e3741c39c7 Mon Sep 17 00:00:00 2001 > From: Wen Congyang <wency@cn.fujitsu.com> > Date: Wed, 4 Jul 2012 16:05:26 +0800 > Subject: [PATCH] debug > > --- > drivers/firmware/memmap.c | 7 +++++++ > 1 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c > index adc0710..993ba3f 100644 > --- a/drivers/firmware/memmap.c > +++ b/drivers/firmware/memmap.c > @@ -21,6 +21,7 @@ > #include <linux/types.h> > #include <linux/bootmem.h> > #include <linux/slab.h> > +#include <linux/mm.h> > > /* > * Data types ------------------------------------------------------------------ > @@ -160,11 +161,17 @@ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) > int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) > { > struct firmware_map_entry *entry; > + struct page *entry_page; > > entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); > if (!entry) > return -ENOMEM; > > + entry_page = virt_to_page(entry); > + printk(KERN_WARNING "flags: %lx\n", entry_page->flags); > + if (PageSlab(entry_page)) { > + printk(KERN_WARNING "page is allocated from slab\n"); > + } > firmware_map_add_entry(start, end, type, entry); > /* create the memmap entry */ > add_sysfs_fw_map_entry(entry); > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c index adc0710..993ba3f 100644 --- a/drivers/firmware/memmap.c +++ b/drivers/firmware/memmap.c @@ -21,6 +21,7 @@ #include <linux/types.h> #include <linux/bootmem.h> #include <linux/slab.h> +#include <linux/mm.h> /* * Data types ------------------------------------------------------------------ @@ -160,11 +161,17 @@ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type) { struct firmware_map_entry *entry; + struct page *entry_page; entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC); if (!entry) return -ENOMEM; + entry_page = virt_to_page(entry); + printk(KERN_WARNING "flags: %lx\n", entry_page->flags); + if (PageSlab(entry_page)) { + printk(KERN_WARNING "page is allocated from slab\n"); + } firmware_map_add_entry(start, end, type, entry); /* create the memmap entry */ add_sysfs_fw_map_entry(entry);