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author | Kip Macy <kmacy@FreeBSD.org> | 2010-05-01 03:41:21 +0000 |
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committer | Kip Macy <kmacy@FreeBSD.org> | 2010-05-01 03:41:21 +0000 |
commit | 0ce3ba8cd58ea437906bcb4cf8c03a4e92a9e8ca (patch) | |
tree | 055150d7db77e6a140f65c3f32c3d103e3e0244a /sys/vm/vm_page.h | |
parent | 483191871b206c25ea7f6182e8b8a8acdda0af24 (diff) | |
download | src-0ce3ba8cd58ea437906bcb4cf8c03a4e92a9e8ca.tar.gz src-0ce3ba8cd58ea437906bcb4cf8c03a4e92a9e8ca.zip |
Update locking comment above vm_page:
- re-assign page queue lock "Q"
- assign page lock "P"
- update several uncommented fields
- observe that hold_count is now protected by the page lock "P"
Notes
Notes:
svn path=/head/; revision=207460
Diffstat (limited to 'sys/vm/vm_page.h')
-rw-r--r-- | sys/vm/vm_page.h | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h index 35a81f8a8d74..51a896f9ae36 100644 --- a/sys/vm/vm_page.h +++ b/sys/vm/vm_page.h @@ -90,20 +90,21 @@ * and sundry status bits. * * Fields in this structure are locked either by the lock on the - * object that the page belongs to (O) or by the lock on the page - * queues (P). + * object that the page belongs to (O), its corresponding page lock (P), + * or by the lock on the page queues (Q). + * */ TAILQ_HEAD(pglist, vm_page); struct vm_page { - TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */ + TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (Q) */ TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ struct vm_page *left; /* splay tree link (O) */ struct vm_page *right; /* splay tree link (O) */ - vm_object_t object; /* which object am I in (O,P)*/ - vm_pindex_t pindex; /* offset into object (O,P) */ + vm_object_t object; /* which object am I in (O,Q)*/ + vm_pindex_t pindex; /* offset into object (O,Q) */ vm_paddr_t phys_addr; /* physical address of page */ struct md_page md; /* machine dependant stuff */ uint8_t queue; /* page queue index */ @@ -111,11 +112,11 @@ struct vm_page { u_short flags; /* see below */ uint8_t order; /* index of the buddy queue */ uint8_t pool; - u_short cow; /* page cow mapping count */ - u_int wire_count; /* wired down maps refs (P) */ - short hold_count; /* page hold count */ + u_short cow; /* page cow mapping count (Q) */ + u_int wire_count; /* wired down maps refs (Q) */ + short hold_count; /* page hold count (P) */ u_short oflags; /* page flags (O) */ - u_char act_count; /* page usage count */ + u_char act_count; /* page usage count (Q) */ u_char busy; /* page busy count (O) */ /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ /* so, on normal X86 kernels, they must be at least 8 bits wide */ |