| vm_page_aflag.9 (147647) | vm_page_aflag.9 (225419) |
|---|---|
| 1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as --- 10 unchanged lines hidden (view full) --- 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" | 1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as --- 10 unchanged lines hidden (view full) --- 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" |
| 27.\" $FreeBSD: head/share/man/man9/vm_page_flag.9 147647 2005-06-28 20:15:19Z hmp $ | 27.\" $FreeBSD: head/share/man/man9/vm_page_aflag.9 225419 2011-09-06 10:40:21Z kib $ |
| 28.\" | 28.\" |
| 29.Dd July 14, 2001 | 29.Dd August 31, 2011 |
| 30.Dt VM_PAGE_FLAG 9 31.Os 32.Sh NAME | 30.Dt VM_PAGE_FLAG 9 31.Os 32.Sh NAME |
| 33.Nm vm_page_flag_clear , vm_page_flag_set 34.Nd "change page flags" | 33.Nm vm_page_aflag_clear , vm_page_aflag_set , vm_page_reference 34.Nd "change page atomic flags" |
| 35.Sh SYNOPSIS 36.In sys/param.h 37.In vm/vm.h 38.In vm/vm_page.h 39.Ft void | 35.Sh SYNOPSIS 36.In sys/param.h 37.In vm/vm.h 38.In vm/vm_page.h 39.Ft void |
| 40.Fn vm_page_flag_clear "vm_page_t m" "unsigned short bits" | 40.Fn vm_page_aflag_clear "vm_page_t m" "uint8_t bits" |
| 41.Ft void | 41.Ft void |
| 42.Fn vm_page_flag_set "vm_page_t m" "unsigned short bits" | 42.Fn vm_page_aflag_set "vm_page_t m" "uint8_t bits" 43.Ft void 44.Fn vm_page_reference "vm_page_t m" |
| 43.Sh DESCRIPTION 44The | 45.Sh DESCRIPTION 46The |
| 45.Fn vm_page_flag_clear 46atomically clears the specified bits on the page's flags. | 47.Fn vm_page_aflag_clear 48atomically clears the specified bits on the page's 49.Va aflags . |
| 47.Pp 48The | 50.Pp 51The |
| 49.Fn vm_page_flag_set 50atomically sets the specified bits on the page's flags. | 52.Fn vm_page_aflag_set 53atomically sets the specified bits on the page's 54.Va aflags . |
| 51.Pp | 55.Pp |
| 56The 57.Fn vm_page_reference m 58call is the same as 59.Bd -literal -offset indent 60vm_page_aflag_set(m, PGA_REFERENCED); 61.Ed 62.Lp 63and is the recommended way to mark the page as referenced from 64third-party kernel modules. 65.Pp 66These functions neither block nor require any locks to be held 67around the calls for correctness. 68.Pp |
|
| 52The functions arguments are: 53.Bl -tag -width ".Fa bits" 54.It Fa m | 69The functions arguments are: 70.Bl -tag -width ".Fa bits" 71.It Fa m |
| 55The page whose flags are updated. | 72The page whose 73.Va aflags 74are updated. |
| 56.It Fa bits 57The bits that are set or cleared on the page's flags. 58.El | 75.It Fa bits 76The bits that are set or cleared on the page's flags. 77.El |
| 78.Pp 79The following 80.Va aflags 81can be set or cleared: 82.Bl -tag -width ".Fa PGA_REFERENCED" 83.It Fa PGA_REFERENCED 84The bit may be set to indicate that the page has been recently accessed. 85For instance, 86.Xr pmap 9 87sets this bit to reflect the accessed attribute of the page mapping 88typically updated by processor's memory management unit on the page access. 89.It Fa PGA_WRITEABLE 90A writeable mapping for the page may exist. 91.El 92.Pp 93Both 94.Dv PGA_REFERENCED 95and 96.Dv PGA_WRITEABLE 97bits are only valid for the managed pages. |
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| 59.Sh AUTHORS 60This manual page was written by 61.An Chad David Aq davidc@acns.ab.ca . | 98.Sh AUTHORS 99This manual page was written by 100.An Chad David Aq davidc@acns.ab.ca . |