Date: Thu, 24 Jan 2008 04:04:13 GMT From: Kip Macy <kmacy@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 133969 for review Message-ID: <200801240404.m0O44DqB061272@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=133969 Change 133969 by kmacy@pandemonium:kmacy:xen31 on 2008/01/24 04:04:04 don't use ptes as a free list for pv chunks keep unused pv chunks in a free list - may need to re-visit for low-mem handling tentatively re-enable pre-faulting Affected files ... .. //depot/projects/xen31/sys/i386/xen/pmap.c#32 edit Differences ... ==== //depot/projects/xen31/sys/i386/xen/pmap.c#32 (text+ko) ==== @@ -225,6 +225,7 @@ static int shpgperproc = PMAP_SHPGPERPROC; struct pv_chunk *pv_chunkbase; /* KVA block for pv_chunks */ +struct pv_chunk *pv_next_unused; /* KVA free block for pv_chunks */ int pv_maxchunks; /* How many chunks we have KVA for */ vm_offset_t pv_vafree; /* freelist stored in the PTE */ @@ -293,6 +294,7 @@ static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t *); static vm_offset_t pmap_kmem_choose(vm_offset_t addr); static boolean_t pmap_is_prefaultable_locked(pmap_t pmap, vm_offset_t addr); +static void pmap_collect(pmap_t locked_pmap, struct vpgqueues *vpq); #if defined(PAE) && !defined(XEN) static void *pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait); @@ -308,8 +310,41 @@ */ CTASSERT(KERNBASE % (1 << 24) == 0); +SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_max, CTLFLAG_RD, &pv_entry_max, 0, + "Max number of PV entries"); +SYSCTL_INT(_vm_pmap, OID_AUTO, shpgperproc, CTLFLAG_RD, &shpgperproc, 0, + "Page share factor per proc"); + +#ifdef PV_STATS +static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail; + +SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_count, CTLFLAG_RD, &pc_chunk_count, 0, + "Current number of pv entry chunks"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_allocs, CTLFLAG_RD, &pc_chunk_allocs, 0, + "Current number of pv entry chunks allocated"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_frees, CTLFLAG_RD, &pc_chunk_frees, 0, + "Current number of pv entry chunks frees"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_tryfail, CTLFLAG_RD, &pc_chunk_tryfail, 0, + "Number of times tried to get a chunk page but failed."); + +static long pv_entry_frees, pv_entry_allocs; +static int pv_entry_spare; + +SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_frees, CTLFLAG_RD, &pv_entry_frees, 0, + "Current number of pv entry frees"); +SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_allocs, CTLFLAG_RD, &pv_entry_allocs, 0, + "Current number of pv entry allocs"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0, + "Current number of spare pv entries"); +static int pmap_collect_inactive, pmap_collect_active; +SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_inactive, CTLFLAG_RD, &pmap_collect_inactive, 0, + "Current number times pmap_collect called on inactive queue"); +SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_active, CTLFLAG_RD, &pmap_collect_active, 0, + "Current number times pmap_collect called on active queue"); +#endif static __inline void pagezero(void *page) @@ -613,45 +648,73 @@ * Because PG_V is never set, there can be no mappings to invalidate. */ static vm_offset_t -pmap_ptelist_alloc(vm_offset_t *head) +pmap_ptelist_alloc(pmap_t pmap, int try, vm_offset_t *head) { - pt_entry_t *pte; vm_offset_t va; + vm_page_t m; + struct vpgqueues *pq; + static vm_pindex_t colour; + + if (head != NULL) { + va = (vm_offset_t) *head; + *head = **(vm_offset_t **)head; + return (va); + } + + if ((uint32_t)pv_next_unused < (uint32_t)((uint8_t *)pv_chunkbase) + pv_maxchunks*PAGE_SIZE) { + va = (vm_offset_t)pv_next_unused; + pv_next_unused++; + } else + return (0); + + /* + * Access to the ptelist "pv_vafree" is synchronized by the page + * queues lock. If "pv_vafree" is currently non-empty, it will + * remain non-empty until pmap_ptelist_alloc() completes. + */ + if (pv_vafree == 0 || (m = vm_page_alloc(NULL, colour, (pq == + &vm_page_queues[PQ_ACTIVE] ? VM_ALLOC_SYSTEM : VM_ALLOC_NORMAL) | + VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { + if (try) { + pv_entry_count--; + PV_STAT(pc_chunk_tryfail++); + return (0); + } + /* + * Reclaim pv entries: At first, destroy mappings to + * inactive pages. After that, if a pv chunk entry + * is still needed, destroy mappings to active pages. + */ + if (pq == NULL) { + PV_STAT(pmap_collect_inactive++); + pq = &vm_page_queues[PQ_INACTIVE]; + } else if (pq == &vm_page_queues[PQ_INACTIVE]) { + PV_STAT(pmap_collect_active++); + pq = &vm_page_queues[PQ_ACTIVE]; + } else + panic("get_pv_entry: increase vm.pmap.shpgperproc"); + pmap_collect(pmap, pq); + return (1); /* ~\0_o/~ */ + } + colour++; + pmap_qenter(va, &m, 1); + if ((m->flags & PG_ZERO) == 0) + pagezero((void *)va); - va = *head; - if (va == 0) - return (va); /* Out of memory */ - pte = vtopte(va); - *head = *pte; - if (*head & PG_V) - panic("pmap_ptelist_alloc: va with PG_V set!"); - *pte = 0; return (va); } static void pmap_ptelist_free(vm_offset_t *head, vm_offset_t va) { - pt_entry_t *pte; - - if (va & PG_V) - panic("pmap_ptelist_free: freeing va with PG_V set!"); - pte = vtopte(va); - *pte = *head; /* virtual! PG_V is 0 though */ + *(vm_offset_t *)va = (vm_offset_t)head; *head = va; } static void pmap_ptelist_init(vm_offset_t *head, void *base, int npages) { - int i; - vm_offset_t va; - *head = 0; - for (i = npages - 1; i >= 0; i--) { - va = (vm_offset_t)base + i * PAGE_SIZE; - pmap_ptelist_free(head, va); - } } @@ -676,7 +739,7 @@ pv_entry_high_water = 9 * (pv_entry_max / 10); pv_maxchunks = MAX(pv_entry_max / _NPCPV, maxproc); - pv_chunkbase = (struct pv_chunk *)kmem_alloc_nofault(kernel_map, + pv_next_unused = pv_chunkbase = (struct pv_chunk *)kmem_alloc_nofault(kernel_map, PAGE_SIZE * pv_maxchunks); if (pv_chunkbase == NULL) panic("pmap_init: not enough kvm for pv chunks"); @@ -690,12 +753,6 @@ } -SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_max, CTLFLAG_RD, &pv_entry_max, 0, - "Max number of PV entries"); -SYSCTL_INT(_vm_pmap, OID_AUTO, shpgperproc, CTLFLAG_RD, &shpgperproc, 0, - "Page share factor per proc"); - /*************************************************** * Low level helper routines..... ***************************************************/ @@ -1882,36 +1939,6 @@ SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_count, CTLFLAG_RD, &pv_entry_count, 0, "Current number of pv entries"); -#ifdef PV_STATS -static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail; - -SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_count, CTLFLAG_RD, &pc_chunk_count, 0, - "Current number of pv entry chunks"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_allocs, CTLFLAG_RD, &pc_chunk_allocs, 0, - "Current number of pv entry chunks allocated"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_frees, CTLFLAG_RD, &pc_chunk_frees, 0, - "Current number of pv entry chunks frees"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pc_chunk_tryfail, CTLFLAG_RD, &pc_chunk_tryfail, 0, - "Number of times tried to get a chunk page but failed."); - -static long pv_entry_frees, pv_entry_allocs; -static int pv_entry_spare; - -SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_frees, CTLFLAG_RD, &pv_entry_frees, 0, - "Current number of pv entry frees"); -SYSCTL_LONG(_vm_pmap, OID_AUTO, pv_entry_allocs, CTLFLAG_RD, &pv_entry_allocs, 0, - "Current number of pv entry allocs"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0, - "Current number of spare pv entries"); - -static int pmap_collect_inactive, pmap_collect_active; - -SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_inactive, CTLFLAG_RD, &pmap_collect_inactive, 0, - "Current number times pmap_collect called on inactive queue"); -SYSCTL_INT(_vm_pmap, OID_AUTO, pmap_collect_active, CTLFLAG_RD, &pmap_collect_active, 0, - "Current number times pmap_collect called on active queue"); -#endif - /* * We are in a serious low memory condition. Resort to * drastic measures to free some pages so we can allocate @@ -1974,7 +2001,6 @@ static void free_pv_entry(pmap_t pmap, pv_entry_t pv) { - vm_page_t m; struct pv_chunk *pc; int idx, field, bit; @@ -1999,10 +2025,6 @@ PV_STAT(pc_chunk_frees++); /* entire chunk is free, return it */ TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); - m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc)); - pmap_qremove((vm_offset_t)pc, 1); - vm_page_unwire(m, 0); - vm_page_free(m); pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc); } @@ -2015,12 +2037,10 @@ { static const struct timeval printinterval = { 60, 0 }; static struct timeval lastprint; - static vm_pindex_t colour; struct vpgqueues *pq; int bit, field; pv_entry_t pv; struct pv_chunk *pc; - vm_page_t m; PMAP_LOCK_ASSERT(pmap, MA_OWNED); mtx_assert(&vm_page_queue_mtx, MA_OWNED); @@ -2056,42 +2076,13 @@ return (pv); } } - /* - * Access to the ptelist "pv_vafree" is synchronized by the page - * queues lock. If "pv_vafree" is currently non-empty, it will - * remain non-empty until pmap_ptelist_alloc() completes. - */ - if (pv_vafree == 0 || (m = vm_page_alloc(NULL, colour, (pq == - &vm_page_queues[PQ_ACTIVE] ? VM_ALLOC_SYSTEM : VM_ALLOC_NORMAL) | - VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { - if (try) { - pv_entry_count--; - PV_STAT(pc_chunk_tryfail++); - return (NULL); - } - /* - * Reclaim pv entries: At first, destroy mappings to - * inactive pages. After that, if a pv chunk entry - * is still needed, destroy mappings to active pages. - */ - if (pq == NULL) { - PV_STAT(pmap_collect_inactive++); - pq = &vm_page_queues[PQ_INACTIVE]; - } else if (pq == &vm_page_queues[PQ_INACTIVE]) { - PV_STAT(pmap_collect_active++); - pq = &vm_page_queues[PQ_ACTIVE]; - } else - panic("get_pv_entry: increase vm.pmap.shpgperproc"); - pmap_collect(pmap, pq); + pc = (struct pv_chunk *)pmap_ptelist_alloc(pmap, try, &pv_vafree); + if (((vm_offset_t)pc) == 1) goto retry; - } + if (((vm_offset_t)pc) == 0) + return (NULL); PV_STAT(pc_chunk_count++); PV_STAT(pc_chunk_allocs++); - colour++; - pc = (struct pv_chunk *)pmap_ptelist_alloc(&pv_vafree); - pmap_qenter((vm_offset_t)pc, &m, 1); - if ((m->flags & PG_ZERO) == 0) - pagezero(pc); pc->pc_pmap = pmap; pc->pc_map[0] = pc_freemask[0] & ~1ul; /* preallocated bit 0 */ for (field = 1; field < _NPCM; field++) @@ -3439,10 +3430,6 @@ PV_STAT(pc_chunk_count--); PV_STAT(pc_chunk_frees++); TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); - m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)pc)); - pmap_qremove((vm_offset_t)pc, 1); - vm_page_unwire(m, 0); - vm_page_free(m); pmap_ptelist_free(&pv_vafree, (vm_offset_t)pc); } } @@ -3502,8 +3489,6 @@ pt_entry_t *pte; boolean_t rv = FALSE; - return (rv); - if (*pmap_pde(pmap, addr)) { pte = vtopte(addr); rv = ((*pte & PG_V) == 0);
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