vm_page_try_to_free (9)

Leading comments

Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.

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(The comments found at the beginning of the groff file "man9/vm_page_try_to_free.9freebsd".)

NAME

vm_page_free vm_page_free_toq vm_page_free_zero vm_page_try_to_free - free a page

SYNOPSIS

In sys/param.h In vm/vm.h In vm/vm_page.h Ft void Fn vm_page_free vm_page_t m Ft void Fn vm_page_free_toq vm_page_t m Ft void Fn vm_page_free_zero vm_page_t m Ft int Fn vm_page_try_to_free vm_page_t m

DESCRIPTION

The Fn vm_page_free_toq function moves a page into the free queue, and disassociates it from its object. If the page is held, wired, already free, or its busy count is not zero, the system will panic. If the PG_ZERO flag is set on the page, it is placed at the end of the free queue; otherwise, it is placed at the front.

If the page's object is of type OBJT_VNODE and it is the last page associated with the object, the underlying vnode may be freed.

The Fn vm_page_free and Fn vm_page_free_zero functions both call Fn vm_page_free_toq to actually free the page, but Fn vm_page_free_zero sets the PG_ZERO flag and Fn vm_page_free clears the PG_ZERO flag prior to the call to Fn vm_page_free_toq .

The Fn vm_page_try_to_free function verifies that the page is not held, wired, busy or dirty, and if so, marks the page as busy, drops any protection that may be set on the page, and frees it.

RETURN VALUES

Fn vm_page_try_to_free returns 1 if it is able to free the page; otherwise, 0 is returned.

SEE ALSO

vm_page_busy9, vm_page_hold9, vm_page_wire9

AUTHORS

This manual page was written by An Chad David Aq davidc@acns.ab.ca .