proc: export more page flags in /proc/kpageflags
Export all page flags faithfully in /proc/kpageflags. 11. KPF_MMAP (pseudo flag) memory mapped page 12. KPF_ANON (pseudo flag) memory mapped page (anonymous) 13. KPF_SWAPCACHE page is in swap cache 14. KPF_SWAPBACKED page is swap/RAM backed 15. KPF_COMPOUND_HEAD (*) 16. KPF_COMPOUND_TAIL (*) 17. KPF_HUGE hugeTLB pages 18. KPF_UNEVICTABLE page is in the unevictable LRU list 19. KPF_HWPOISON(TBD) hardware detected corruption 20. KPF_NOPAGE (pseudo flag) no page frame at the address 32-39. more obscure flags for kernel developers (*) For compound pages, exporting _both_ head/tail info enables users to tell where a compound page starts/ends, and its order. The accompanying page-types tool will handle the details like decoupling overloaded flags and hiding obscure flags to normal users. Thanks to KOSAKI and Andi for their valuable recommendations! Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Wu Fengguang
Linus Torvalds
parent
ed7ce0f102
commit
1779754959
1 changed files with 118 additions and 30 deletions
148
fs/proc/page.c
148
fs/proc/page.c
|
|
@ -72,19 +72,124 @@ static const struct file_operations proc_kpagecount_operations = {
|
|||
|
||||
/* These macros are used to decouple internal flags from exported ones */
|
||||
|
||||
#define KPF_LOCKED 0
|
||||
#define KPF_ERROR 1
|
||||
#define KPF_REFERENCED 2
|
||||
#define KPF_UPTODATE 3
|
||||
#define KPF_DIRTY 4
|
||||
#define KPF_LRU 5
|
||||
#define KPF_ACTIVE 6
|
||||
#define KPF_SLAB 7
|
||||
#define KPF_WRITEBACK 8
|
||||
#define KPF_RECLAIM 9
|
||||
#define KPF_BUDDY 10
|
||||
#define KPF_LOCKED 0
|
||||
#define KPF_ERROR 1
|
||||
#define KPF_REFERENCED 2
|
||||
#define KPF_UPTODATE 3
|
||||
#define KPF_DIRTY 4
|
||||
#define KPF_LRU 5
|
||||
#define KPF_ACTIVE 6
|
||||
#define KPF_SLAB 7
|
||||
#define KPF_WRITEBACK 8
|
||||
#define KPF_RECLAIM 9
|
||||
#define KPF_BUDDY 10
|
||||
|
||||
#define kpf_copy_bit(flags, dstpos, srcpos) (((flags >> srcpos) & 1) << dstpos)
|
||||
/* 11-20: new additions in 2.6.31 */
|
||||
#define KPF_MMAP 11
|
||||
#define KPF_ANON 12
|
||||
#define KPF_SWAPCACHE 13
|
||||
#define KPF_SWAPBACKED 14
|
||||
#define KPF_COMPOUND_HEAD 15
|
||||
#define KPF_COMPOUND_TAIL 16
|
||||
#define KPF_HUGE 17
|
||||
#define KPF_UNEVICTABLE 18
|
||||
#define KPF_NOPAGE 20
|
||||
|
||||
/* kernel hacking assistances
|
||||
* WARNING: subject to change, never rely on them!
|
||||
*/
|
||||
#define KPF_RESERVED 32
|
||||
#define KPF_MLOCKED 33
|
||||
#define KPF_MAPPEDTODISK 34
|
||||
#define KPF_PRIVATE 35
|
||||
#define KPF_PRIVATE_2 36
|
||||
#define KPF_OWNER_PRIVATE 37
|
||||
#define KPF_ARCH 38
|
||||
#define KPF_UNCACHED 39
|
||||
|
||||
static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
|
||||
{
|
||||
return ((kflags >> kbit) & 1) << ubit;
|
||||
}
|
||||
|
||||
static u64 get_uflags(struct page *page)
|
||||
{
|
||||
u64 k;
|
||||
u64 u;
|
||||
|
||||
/*
|
||||
* pseudo flag: KPF_NOPAGE
|
||||
* it differentiates a memory hole from a page with no flags
|
||||
*/
|
||||
if (!page)
|
||||
return 1 << KPF_NOPAGE;
|
||||
|
||||
k = page->flags;
|
||||
u = 0;
|
||||
|
||||
/*
|
||||
* pseudo flags for the well known (anonymous) memory mapped pages
|
||||
*
|
||||
* Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
|
||||
* simple test in page_mapped() is not enough.
|
||||
*/
|
||||
if (!PageSlab(page) && page_mapped(page))
|
||||
u |= 1 << KPF_MMAP;
|
||||
if (PageAnon(page))
|
||||
u |= 1 << KPF_ANON;
|
||||
|
||||
/*
|
||||
* compound pages: export both head/tail info
|
||||
* they together define a compound page's start/end pos and order
|
||||
*/
|
||||
if (PageHead(page))
|
||||
u |= 1 << KPF_COMPOUND_HEAD;
|
||||
if (PageTail(page))
|
||||
u |= 1 << KPF_COMPOUND_TAIL;
|
||||
if (PageHuge(page))
|
||||
u |= 1 << KPF_HUGE;
|
||||
|
||||
u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
|
||||
|
||||
/*
|
||||
* Caveats on high order pages:
|
||||
* PG_buddy will only be set on the head page; SLUB/SLQB do the same
|
||||
* for PG_slab; SLOB won't set PG_slab at all on compound pages.
|
||||
*/
|
||||
u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
|
||||
u |= kpf_copy_bit(k, KPF_BUDDY, PG_buddy);
|
||||
|
||||
u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
|
||||
u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
|
||||
u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
|
||||
u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
|
||||
|
||||
u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
|
||||
u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
|
||||
u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
|
||||
u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
|
||||
|
||||
u |= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
|
||||
u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
|
||||
|
||||
#ifdef CONFIG_UNEVICTABLE_LRU
|
||||
u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
|
||||
u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
|
||||
u |= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
|
||||
#endif
|
||||
|
||||
u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
|
||||
u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
|
||||
u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
|
||||
u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
|
||||
u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
|
||||
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
|
||||
|
||||
return u;
|
||||
};
|
||||
|
||||
static ssize_t kpageflags_read(struct file *file, char __user *buf,
|
||||
size_t count, loff_t *ppos)
|
||||
|
|
@ -94,7 +199,6 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
|
|||
unsigned long src = *ppos;
|
||||
unsigned long pfn;
|
||||
ssize_t ret = 0;
|
||||
u64 kflags, uflags;
|
||||
|
||||
pfn = src / KPMSIZE;
|
||||
count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
|
||||
|
|
@ -106,24 +210,8 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
|
|||
ppage = pfn_to_page(pfn);
|
||||
else
|
||||
ppage = NULL;
|
||||
if (!ppage)
|
||||
kflags = 0;
|
||||
else
|
||||
kflags = ppage->flags;
|
||||
|
||||
uflags = kpf_copy_bit(kflags, KPF_LOCKED, PG_locked) |
|
||||
kpf_copy_bit(kflags, KPF_ERROR, PG_error) |
|
||||
kpf_copy_bit(kflags, KPF_REFERENCED, PG_referenced) |
|
||||
kpf_copy_bit(kflags, KPF_UPTODATE, PG_uptodate) |
|
||||
kpf_copy_bit(kflags, KPF_DIRTY, PG_dirty) |
|
||||
kpf_copy_bit(kflags, KPF_LRU, PG_lru) |
|
||||
kpf_copy_bit(kflags, KPF_ACTIVE, PG_active) |
|
||||
kpf_copy_bit(kflags, KPF_SLAB, PG_slab) |
|
||||
kpf_copy_bit(kflags, KPF_WRITEBACK, PG_writeback) |
|
||||
kpf_copy_bit(kflags, KPF_RECLAIM, PG_reclaim) |
|
||||
kpf_copy_bit(kflags, KPF_BUDDY, PG_buddy);
|
||||
|
||||
if (put_user(uflags, out)) {
|
||||
if (put_user(get_uflags(ppage), out)) {
|
||||
ret = -EFAULT;
|
||||
break;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue