- export raw page loan out routine as uvm_loanuobjpages. (for nfsd)
- put code for loan-breaking into a function, uvm_loanbreak.
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yamt
parent
91ccfbdaab
commit
dea6f8bc9a
@ -1,4 +1,4 @@
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/* $NetBSD: uvm_loan.c,v 1.41 2003/03/05 01:52:41 thorpej Exp $ */
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/* $NetBSD: uvm_loan.c,v 1.42 2003/05/03 17:54:32 yamt Exp $ */
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/*
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*
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@ -39,7 +39,7 @@
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: uvm_loan.c,v 1.41 2003/03/05 01:52:41 thorpej Exp $");
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__KERNEL_RCSID(0, "$NetBSD: uvm_loan.c,v 1.42 2003/05/03 17:54:32 yamt Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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@ -418,6 +418,42 @@ uvm_loananon(ufi, output, flags, anon)
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return (1);
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}
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/*
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* uvm_loanuobjpages: loan pages from a uobj out (O->K)
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*
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* => called with uobj locked.
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* => caller should own the pages.
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*/
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void
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uvm_loanuobjpages(pgpp, npages)
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struct vm_page **pgpp;
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int npages;
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{
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int i;
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for (i = 0; i < npages; i++) {
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struct vm_page *pg = pgpp[i];
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KASSERT(pg->uobject != NULL);
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KASSERT(!(pg->flags & (PG_RELEASED|PG_PAGEOUT)));
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LOCK_ASSERT(simple_lock_held(&pg->uobject->vmobjlock));
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KASSERT(pg->flags & PG_BUSY);
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uvm_lock_pageq();
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if (pg->loan_count == 0) {
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pmap_page_protect(pg, VM_PROT_READ);
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}
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pg->loan_count++;
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uvm_pagedequeue(pg);
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uvm_unlock_pageq();
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if (pg->flags & PG_WANTED) {
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wakeup(pg);
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}
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pg->flags &= ~(PG_WANTED|PG_BUSY);
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UVM_PAGE_OWN(pg, NULL);
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}
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}
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/*
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* uvm_loanuobj: loan a page from a uobj out
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*
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@ -545,18 +581,7 @@ uvm_loanuobj(ufi, output, flags, va)
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*/
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if ((flags & UVM_LOAN_TOANON) == 0) {
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uvm_lock_pageq();
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if (pg->loan_count == 0) {
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pmap_page_protect(pg, VM_PROT_READ);
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}
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pg->loan_count++;
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uvm_pagedequeue(pg);
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uvm_unlock_pageq();
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if (pg->flags & PG_WANTED) {
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wakeup(pg);
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}
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pg->flags &= ~(PG_WANTED|PG_BUSY);
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UVM_PAGE_OWN(pg, NULL);
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uvm_loanuobjpages(&pg, 1);
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**output = pg;
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(*output)++;
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return (1);
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@ -905,3 +930,75 @@ uvm_loan_init(void)
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TAILQ_INIT(&uvm_loanzero_object.memq);
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uvm_loanzero_object.pgops = &ulz_pager;
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}
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/*
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* uvm_loanbreak: break loan on a uobj page
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*
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* => called with uobj locked
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* => the page should be busy
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* => return value:
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* newly allocated page if succeeded
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*/
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struct vm_page *
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uvm_loanbreak(struct vm_page *uobjpage)
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{
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struct vm_page *pg;
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struct uvm_object *uobj = uobjpage->uobject;
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voff_t offset;
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KASSERT(uobj != NULL);
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LOCK_ASSERT(simple_lock_held(&uobj->vmobjlock));
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KASSERT(uobjpage->flags & PG_BUSY);
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/* alloc new un-owned page */
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pg = uvm_pagealloc(NULL, 0, NULL, 0);
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if (pg == NULL)
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return NULL;
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/*
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* copy the data from the old page to the new
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* one and clear the fake/clean flags on the
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* new page (keep it busy). force a reload
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* of the old page by clearing it from all
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* pmaps. then lock the page queues to
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* rename the pages.
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*/
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uvm_pagecopy(uobjpage, pg); /* old -> new */
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pg->flags &= ~(PG_FAKE|PG_CLEAN);
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pmap_page_protect(uobjpage, VM_PROT_NONE);
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if (uobjpage->flags & PG_WANTED)
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wakeup(uobjpage);
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/* uobj still locked */
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uobjpage->flags &= ~(PG_WANTED|PG_BUSY);
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UVM_PAGE_OWN(uobjpage, NULL);
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uvm_lock_pageq();
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offset = uobjpage->offset;
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uvm_pagerealloc(uobjpage, NULL, 0);
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/*
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* if the page is no longer referenced by
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* an anon (i.e. we are breaking an O->K
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* loan), then remove it from any pageq's.
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*/
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if (uobjpage->uanon == NULL)
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uvm_pagedequeue(uobjpage);
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/*
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* at this point we have absolutely no
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* control over uobjpage
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*/
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/* install new page */
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uvm_pageactivate(pg);
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uvm_pagerealloc(pg, uobj, offset);
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uvm_unlock_pageq();
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/*
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* done! loan is broken and "pg" is
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* PG_BUSY. it can now replace uobjpage.
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*/
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return pg;
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}
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@ -1,4 +1,4 @@
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/* $NetBSD: uvm_loan.h,v 1.10 2003/03/04 06:18:54 thorpej Exp $ */
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/* $NetBSD: uvm_loan.h,v 1.11 2003/05/03 17:54:32 yamt Exp $ */
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/*
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*
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@ -53,6 +53,8 @@
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void uvm_loan_init __P((void));
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int uvm_loan __P((struct vm_map *, vaddr_t, vsize_t, void *, int));
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void uvm_unloan __P((void *, int, int));
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void uvm_loanuobjpages __P((struct vm_page **, int));
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struct vm_page *uvm_loanbreak __P((struct vm_page *));
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#endif /* _KERNEL */
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