Date: Sat, 28 Jan 2006 00:21:40 GMT From: Alan Cox <alc@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 90537 for review Message-ID: <200601280021.k0S0LeuP067537@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=90537 Change 90537 by alc@alc_home on 2006/01/28 00:21:15 Introduce buddy_unfree(). It is used to yank a cache state page out of the buddy queues. Affected files ... .. //depot/projects/superpages/src/sys/vm/vm_buddy.c#4 edit .. //depot/projects/superpages/src/sys/vm/vm_buddy.h#4 edit Differences ... ==== //depot/projects/superpages/src/sys/vm/vm_buddy.c#4 (text+ko) ==== @@ -253,6 +253,54 @@ } /* + * Extract the give page from the buddy queues. + */ +boolean_t +buddy_unfree(vm_page_t m) +{ + vm_paddr_t half; + vm_page_t buddy, other; + int q; + + KASSERT(m->flags & PG_CACHE, ("xxx")); + buddy = m; + mtx_lock_spin(&vm_page_queue_free_mtx); + for (q = 0; (buddy->queue - buddy->buddyq) != PQ_BUDDY && + q < BUDDY_QUEUES; q++) { + buddy = PHYS_TO_VM_PAGE(m->phys_addr & + (~(vm_paddr_t)0 << (PAGE_SHIFT + q))); + } + if (q == BUDDY_QUEUES || buddy->buddyq < q) { + mtx_unlock_spin(&vm_page_queue_free_mtx); + return (FALSE); + } + q = buddy->buddyq; + + /* + * m is in the free list as part of a chunk of size 1<<q whose + * first page is buddy; now we only have to take m out of + * there. For that, we remove the whole chunk, return the half + * where m is not, and iterate. + */ + buddy_remove(buddy); + while (q > 0) { + q--; + half = buddy->phys_addr ^ (1 << (PAGE_SHIFT + q)); + if (m->phys_addr < half) + other = PHYS_TO_VM_PAGE(half); + else { + other = buddy; + buddy = PHYS_TO_VM_PAGE(half); + } + buddy_insert(q, other); + } + cnt.v_free_count--; + mtx_unlock_spin(&vm_page_queue_free_mtx); + KASSERT(buddy == m, ("yyy")); + return (TRUE); +} + +/* * */ vm_page_t ==== //depot/projects/superpages/src/sys/vm/vm_buddy.h#4 (text+ko) ==== @@ -6,3 +6,4 @@ vm_page_t buddy_alloc_locked(int magn, boolean_t prefer_zero); void buddy_free(vm_page_t m, int magn); void buddy_free_locked(vm_page_t m, int magn); +boolean_t buddy_unfree(vm_page_t m);help
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