Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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.Dd August 23, 2013 .Dt VM_PAGE_GRAB 9 .Os .Sh NAME .Nm vm_page_grab .Nd "returns a page from an object" .Sh SYNOPSIS n sys/param.h n vm/vm.h n vm/vm_page.h .Ft vm_page_t .Fn vm_page_grab "vm_object_t object" "vm_pindex_t pindex" "int allocflags" .Sh DESCRIPTION The .Fn vm_page_grab function returns the page at .Fa pindex from the given object. If the page exists and is busy, .Fn vm_page_grab will sleep while waiting for it. If the page does not exist, it is allocated. The function sleeps until the allocation request can be satisfied.

p The function requires the .Fa object to be locked on entry, and returns with the object locked. If the .Fn vm_page_grab function sleeps for any reason, the object lock is temporary dropped.

p The .Fn vm_page_grab supports all of the flags supported by .Xr vm_page_alloc 9 . In addition, .Fn vm_page_grab supports the following flags: l -tag -width ".Dv VM_ALLOC_IGN_SBUSY" t Dv VM_ALLOC_IGN_SBUSY When waiting for the busy state of the existing page to drain, only test for exclusive busy; ignore the shared busy counter. .El .Sh RETURN VALUES The .Fn vm_page_grab always returns the page. .Sh SEE ALSO .Xr vm_page_alloc 9 .Sh AUTHORS This manual page was written by .An Chad David Aq davidc@acns.ab.ca .