| vm_page_bits.9 (87182) | vm_page_bits.9 (87857) |
|---|---|
| 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_bits.9 87182 2001-12-02 02:13:35Z alfred $ | 27.\" $FreeBSD: head/share/man/man9/vm_page_bits.9 87857 2001-12-14 09:11:13Z ru $ |
| 28.\" 29.Dd December 1, 2001 30.Dt VM_PAGE_BITS 9 31.Os 32.Sh NAME 33.Nm vm_page_bits , 34.Nm vm_page_set_validclean , 35.Nm vm_page_clear_dirty , --- 31 unchanged lines hidden (view full) --- 67calculates the bits representing the 68.Dv DEV_BSIZE 69range of bytes between 70.Fa base 71and 72.Fa size . 73The byte range is expected to be within a single page, and if 74.Fa size | 28.\" 29.Dd December 1, 2001 30.Dt VM_PAGE_BITS 9 31.Os 32.Sh NAME 33.Nm vm_page_bits , 34.Nm vm_page_set_validclean , 35.Nm vm_page_clear_dirty , --- 31 unchanged lines hidden (view full) --- 67calculates the bits representing the 68.Dv DEV_BSIZE 69range of bytes between 70.Fa base 71and 72.Fa size . 73The byte range is expected to be within a single page, and if 74.Fa size |
| 75is zero no bits will be set. | 75is zero, no bits will be set. |
| 76.Pp | 76.Pp |
| 77.\" ------------------- VM_PAGE_SET_VALIDCLEAN ------------------- | |
| 78.Fn vm_page_set_validclean 79flags the byte range between 80.Fa base 81and 82.Fa size 83as valid and clean. 84The range is expected to be 85.Dv DEV_BSIZE 86aligned and no larger than 87.Dv PAGE_SIZE . 88If it is not properly aligned, any unaligned chucks of the 89.Dv DEV_BSIZE 90blocks at the beginning and end of the range will be zeroed. 91.Pp 92If 93.Fa base 94is zero and 95.Fa size | 77.Fn vm_page_set_validclean 78flags the byte range between 79.Fa base 80and 81.Fa size 82as valid and clean. 83The range is expected to be 84.Dv DEV_BSIZE 85aligned and no larger than 86.Dv PAGE_SIZE . 87If it is not properly aligned, any unaligned chucks of the 88.Dv DEV_BSIZE 89blocks at the beginning and end of the range will be zeroed. 90.Pp 91If 92.Fa base 93is zero and 94.Fa size |
| 96is one page the modified bit in the page map is cleared; as well, | 95is one page, the modified bit in the page map is cleared; as well, |
| 97the 98.Dv PG_NOSYNC 99flag is cleared. 100.Pp 101.Fn vm_page_clear_dirty 102clears the dirty bits within a page in the range between 103.Fa base 104and --- 11 unchanged lines hidden (view full) --- 116.Fa size 117in the page. 118The bits are calculated by calling 119.Fn vm_page_bits . 120As well as clearing the bits within the page, the generation 121number within the object holding the page is incremented. 122.Pp 123.Fn vm_page_zero_invalid | 96the 97.Dv PG_NOSYNC 98flag is cleared. 99.Pp 100.Fn vm_page_clear_dirty 101clears the dirty bits within a page in the range between 102.Fa base 103and --- 11 unchanged lines hidden (view full) --- 115.Fa size 116in the page. 117The bits are calculated by calling 118.Fn vm_page_bits . 119As well as clearing the bits within the page, the generation 120number within the object holding the page is incremented. 121.Pp 122.Fn vm_page_zero_invalid |
| 124zeros all of the blocks within the page that are currently 125flaged as invalid. | 123zeroes all of the blocks within the page that are currently 124flagged as invalid. |
| 126If 127.Fa setvalid | 125If 126.Fa setvalid |
| 128is TRUE, all of the valid bits within the page are set. | 127is 128.Dv TRUE , 129all of the valid bits within the page are set. |
| 129.Pp 130In some cases, such as NFS, the valid bits cannot be set 131in order to maintain cache consistency. 132.Pp 133.Fn vm_page_is_valid 134checks to determine if the all of the 135.Dv DEV_BSIZE 136blocks between 137.Fa base 138and 139.Fa size 140of the page are valid. 141If 142.Fa size 143is zero and the page is entirely invalid 144.Fn vm_page_is_valid | 130.Pp 131In some cases, such as NFS, the valid bits cannot be set 132in order to maintain cache consistency. 133.Pp 134.Fn vm_page_is_valid 135checks to determine if the all of the 136.Dv DEV_BSIZE 137blocks between 138.Fa base 139and 140.Fa size 141of the page are valid. 142If 143.Fa size 144is zero and the page is entirely invalid 145.Fn vm_page_is_valid |
| 145will return TRUE, in all other cases 146a size of zero will return FALSE. | 146will return 147.Dv TRUE , 148in all other cases a size of zero will return 149.Dv FALSE . |
| 147.Pp 148.Fn vm_page_test_dirty 149checks if a page has been modified via any of its physical maps, | 150.Pp 151.Fn vm_page_test_dirty 152checks if a page has been modified via any of its physical maps, |
| 150and if so flags the entire page as dirty. | 153and if so, flags the entire page as dirty. |
| 151.Fn vm_page_dirty 152is called to modify the dirty bits. 153.Pp 154.Fn vm_page_dirty 155flags the entire page as dirty. 156It is expected that the page is not currently on the cache queue. 157.Pp 158.Fn vm_page_undirty 159clears all of the dirty bits in a page. 160.Sh NOTES 161None of these functions are allowed to block. 162.Sh AUTHORS 163This man page was written by 164.An Chad David Aq davidc@acns.ab.ca . | 154.Fn vm_page_dirty 155is called to modify the dirty bits. 156.Pp 157.Fn vm_page_dirty 158flags the entire page as dirty. 159It is expected that the page is not currently on the cache queue. 160.Pp 161.Fn vm_page_undirty 162clears all of the dirty bits in a page. 163.Sh NOTES 164None of these functions are allowed to block. 165.Sh AUTHORS 166This man page was written by 167.An Chad David Aq davidc@acns.ab.ca . |