Use the pool allocator for pv_entry structures. Set a (patchable/config'able)
low water mark on the pool, so we have some chance of crawling along in extreme memory shortages.
This commit is contained in:
thorpej
parent
ed4224c64e
commit
66324de865
@ -1,4 +1,4 @@
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/* $NetBSD: pmap.c,v 1.94 1999/05/17 16:22:57 thorpej Exp $ */
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/* $NetBSD: pmap.c,v 1.95 1999/05/21 23:07:59 thorpej Exp $ */
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/*-
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* Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
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@ -155,7 +155,7 @@
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#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
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__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.94 1999/05/17 16:22:57 thorpej Exp $");
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__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.95 1999/05/21 23:07:59 thorpej Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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@ -267,13 +267,10 @@ u_long pmap_ncpuids;
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struct pv_head *pv_table;
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int pv_table_npages;
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int pmap_npvppg; /* number of PV entries per page */
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/*
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* Free list of pages for use by the physical->virtual entry memory allocator.
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*/
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TAILQ_HEAD(pv_page_list, pv_page) pv_page_freelist;
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int pv_nfree;
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#ifndef PMAP_PV_LOWAT
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#define PMAP_PV_LOWAT 16
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#endif
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int pmap_pv_lowat = PMAP_PV_LOWAT;
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/*
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* List of all pmaps, used to update them when e.g. additional kernel
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@ -287,6 +284,7 @@ LIST_HEAD(, pmap) pmap_all_pmaps;
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struct pool pmap_pmap_pool;
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struct pool pmap_asn_pool;
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struct pool pmap_asngen_pool;
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struct pool pmap_pv_pool;
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/*
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* Canonical names for PGU_* constants.
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@ -385,9 +383,6 @@ u_long pmap_asn_generation[ALPHA_MAXPROCS]; /* current ASN generation */
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* * pvh_slock (per-pv_head) - This lock protects the PV list
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* for a specified managed page.
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*
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* * pmap_pvalloc_slock - This lock protects the data structures
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* which manage the PV entry allocator.
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*
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* * pmap_all_pmaps_slock - This lock protects the global list of
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* all pmaps.
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*
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@ -400,7 +395,6 @@ u_long pmap_asn_generation[ALPHA_MAXPROCS]; /* current ASN generation */
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* an interface function).
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*/
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struct lock pmap_main_lock;
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struct simplelock pmap_pvalloc_slock;
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struct simplelock pmap_all_pmaps_slock;
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#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
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@ -506,7 +500,8 @@ void pmap_pv_enter __P((pmap_t, paddr_t, vaddr_t, boolean_t));
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void pmap_pv_remove __P((pmap_t, paddr_t, vaddr_t, boolean_t));
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struct pv_entry *pmap_pv_alloc __P((void));
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void pmap_pv_free __P((struct pv_entry *));
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void pmap_pv_collect __P((void));
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void *pmap_pv_page_alloc __P((u_long, int, int));
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void pmap_pv_page_free __P((void *, u_long, int));
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#ifdef DEBUG
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void pmap_pv_dump __P((paddr_t));
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#endif
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@ -873,6 +868,9 @@ pmap_bootstrap(ptaddr, maxasn, ncpuids)
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pool_init(&pmap_asngen_pool, pmap_ncpuids * sizeof(u_long), 0, 0, 0,
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"pmasngenpl",
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0, pool_page_alloc_nointr, pool_page_free_nointr, M_VMPMAP);
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pool_init(&pmap_pv_pool, sizeof(struct pv_entry), 0, 0, 0, "pvpl",
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0, pmap_pv_page_alloc, pmap_pv_page_free, M_VMPMAP);
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LIST_INIT(&pmap_all_pmaps);
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/*
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@ -888,7 +886,6 @@ pmap_bootstrap(ptaddr, maxasn, ncpuids)
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* Initialize the locks.
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*/
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lockinit(&pmap_main_lock, PVM, "pmaplk", 0, 0);
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simple_lock_init(&pmap_pvalloc_slock);
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simple_lock_init(&pmap_all_pmaps_slock);
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/*
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@ -1061,13 +1058,6 @@ pmap_init()
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printf("pmap_init()\n");
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#endif
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/*
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* Compute how many PV entries will fit in a single
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* physical page of memory.
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*/
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pmap_npvppg = (PAGE_SIZE - sizeof(struct pv_page_info)) /
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sizeof(struct pv_entry);
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/* initialize protection array */
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alpha_protection_init();
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@ -1083,9 +1073,11 @@ pmap_init()
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}
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/*
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* Intialize the pv_page free list.
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* Set a low water mark on the pv_entry pool, so that we are
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* more likely to have these around even in extreme memory
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* starvation.
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*/
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TAILQ_INIT(&pv_page_freelist);
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pool_setlowat(&pmap_pv_pool, pmap_pv_lowat);
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/*
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* Now it is safe to enable pv entry recording.
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@ -2147,11 +2139,6 @@ pmap_collect(pmap)
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* all necessary locking.
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*/
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pmap_remove(pmap, VM_MIN_ADDRESS, VM_MAX_ADDRESS);
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#ifdef notyet
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/* Go compact and garbage-collect the pv_table. */
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pmap_pv_collect();
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#endif
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}
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/*
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@ -3090,41 +3077,16 @@ pmap_pv_remove(pmap, pa, va, dolock)
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struct pv_entry *
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pmap_pv_alloc()
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{
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paddr_t pvppa;
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struct pv_page *pvp;
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struct pv_entry *pv;
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int i;
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simple_lock(&pmap_pvalloc_slock);
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pv = pool_get(&pmap_pv_pool, PR_NOWAIT);
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if (pv != NULL)
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return (pv);
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if (pv_nfree == 0) {
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/*
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* No free pv_entry's; allocate a new pv_page.
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*/
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pvppa = pmap_physpage_alloc(PGU_PVENT);
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pvp = (struct pv_page *)ALPHA_PHYS_TO_K0SEG(pvppa);
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LIST_INIT(&pvp->pvp_pgi.pgi_freelist);
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for (i = 0; i < pmap_npvppg; i++)
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LIST_INSERT_HEAD(&pvp->pvp_pgi.pgi_freelist,
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&pvp->pvp_pv[i], pv_list);
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pv_nfree += pvp->pvp_pgi.pgi_nfree = pmap_npvppg;
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TAILQ_INSERT_HEAD(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
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}
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--pv_nfree;
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pvp = TAILQ_FIRST(&pv_page_freelist);
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if (--pvp->pvp_pgi.pgi_nfree == 0)
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TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
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pv = LIST_FIRST(&pvp->pvp_pgi.pgi_freelist);
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#ifdef DIAGNOSTIC
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if (pv == NULL)
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panic("pmap_pv_alloc: pgi_nfree inconsistent");
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#endif
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LIST_REMOVE(pv, pv_list);
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simple_unlock(&pmap_pvalloc_slock);
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return (pv);
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/*
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* XXX Should try to steal a pv_entry from another mapping.
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*/
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panic("pmap_pv_alloc: unable to allocate a pv_entry");
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}
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/*
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@ -3136,139 +3098,39 @@ void
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pmap_pv_free(pv)
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struct pv_entry *pv;
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{
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paddr_t pvppa;
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struct pv_page *pvp;
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int nfree;
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simple_lock(&pmap_pvalloc_slock);
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pvp = (struct pv_page *) trunc_page(pv);
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nfree = ++pvp->pvp_pgi.pgi_nfree;
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if (nfree == pmap_npvppg) {
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/*
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* We've freed all of the pv_entry's in this pv_page.
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* Free the pv_page back to the system.
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*/
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pv_nfree -= pmap_npvppg - 1;
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TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
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pvppa = ALPHA_K0SEG_TO_PHYS((vaddr_t)pvp);
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pmap_physpage_free(pvppa);
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} else {
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if (nfree == 1)
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TAILQ_INSERT_TAIL(&pv_page_freelist, pvp,
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pvp_pgi.pgi_list);
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LIST_INSERT_HEAD(&pvp->pvp_pgi.pgi_freelist, pv, pv_list);
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++pv_nfree;
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}
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simple_unlock(&pmap_pvalloc_slock);
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pool_put(&pmap_pv_pool, pv);
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}
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/*
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* pmap_pv_collect:
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* pmap_pv_page_alloc:
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*
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* Compact the pv_table and release any completely free
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* pv_page's back to the system.
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* Allocate a page for the pv_entry pool.
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*/
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void *
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pmap_pv_page_alloc(size, flags, mtype)
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u_long size;
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int flags, mtype;
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{
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paddr_t pg;
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pg = pmap_physpage_alloc(PGU_PVENT);
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return ((void *)ALPHA_PHYS_TO_K0SEG(pg));
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}
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/*
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* pmap_pv_page_free:
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*
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* Free a pv_entry pool page.
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*/
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void
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pmap_pv_collect()
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pmap_pv_page_free(v, size, mtype)
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void *v;
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u_long size;
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int mtype;
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{
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struct pv_page_list pv_page_collectlist;
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struct pv_page *pvp, *npvp;
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struct pv_head *pvh;
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struct pv_entry *pv, *nextpv, *newpv;
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paddr_t pvppa;
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int s;
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TAILQ_INIT(&pv_page_collectlist);
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simple_lock(&pmap_pvalloc_slock);
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/*
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* Find pv_page's that have more than 1/3 of their pv_entry's free.
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* Remove them from the list of available pv_page's and place them
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* on the collection list.
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*/
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for (pvp = TAILQ_FIRST(&pv_page_freelist); pvp != NULL; pvp = npvp) {
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/*
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* Abort if we can't allocate enough new pv_entry's
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* to clean up a pv_page.
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*/
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if (pv_nfree < pmap_npvppg)
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break;
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npvp = TAILQ_NEXT(pvp, pvp_pgi.pgi_list);
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if (pvp->pvp_pgi.pgi_nfree > pmap_npvppg / 3) {
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TAILQ_REMOVE(&pv_page_freelist, pvp, pvp_pgi.pgi_list);
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TAILQ_INSERT_TAIL(&pv_page_collectlist, pvp,
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pvp_pgi.pgi_list);
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pv_nfree -= pvp->pvp_pgi.pgi_nfree;
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pvp->pvp_pgi.pgi_nfree = -1;
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}
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}
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if (TAILQ_FIRST(&pv_page_collectlist) == NULL) {
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simple_unlock(&pmap_pvalloc_slock);
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return;
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}
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/*
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* Now, scan all pv_entry's, looking for ones which live in one
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* of the condemed pv_page's.
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*/
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for (pvh = &pv_table[pv_table_npages - 1]; pvh >= &pv_table[0]; pvh--) {
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if (LIST_FIRST(&pvh->pvh_list) == NULL)
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continue;
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s = splimp(); /* XXX needed w/ PMAP_NEW? */
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for (pv = LIST_FIRST(&pvh->pvh_list); pv != NULL;
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pv = nextpv) {
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nextpv = LIST_NEXT(pv, pv_list);
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pvp = (struct pv_page *) trunc_page(pv);
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if (pvp->pvp_pgi.pgi_nfree == -1) {
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/*
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* Found one! Grab a new pv_entry from
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* an eligible pv_page.
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*/
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pvp = TAILQ_FIRST(&pv_page_freelist);
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if (--pvp->pvp_pgi.pgi_nfree == 0) {
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TAILQ_REMOVE(&pv_page_freelist, pvp,
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pvp_pgi.pgi_list);
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}
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newpv = LIST_FIRST(&pvp->pvp_pgi.pgi_freelist);
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LIST_REMOVE(newpv, pv_list);
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#ifdef DIAGNOSTIC
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if (newpv == NULL)
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panic("pmap_pv_collect: pgi_nfree inconsistent");
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#endif
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/*
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* Remove the doomed pv_entry from its
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* pv_list and copy its contents to
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* the new entry.
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*/
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LIST_REMOVE(pv, pv_list);
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*newpv = *pv;
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/*
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* Now insert the new pv_entry into
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* the list.
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*/
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LIST_INSERT_HEAD(&pvh->pvh_list, newpv,
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pv_list);
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}
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}
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splx(s);
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}
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simple_unlock(&pmap_pvalloc_slock);
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/*
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* Now free all of the pages we've collected.
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*/
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for (pvp = TAILQ_FIRST(&pv_page_collectlist); pvp != NULL; pvp = npvp) {
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npvp = TAILQ_NEXT(pvp, pvp_pgi.pgi_list);
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pvppa = ALPHA_K0SEG_TO_PHYS((vaddr_t)pvp);
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pmap_physpage_free(pvppa);
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}
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pmap_physpage_free(ALPHA_K0SEG_TO_PHYS((vaddr_t)v));
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}
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/******************** misc. functions ********************/
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@ -1,4 +1,4 @@
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/* $NetBSD: pmap.h,v 1.27 1999/04/15 22:15:39 thorpej Exp $ */
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/* $NetBSD: pmap.h,v 1.28 1999/05/21 23:08:00 thorpej Exp $ */
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/*-
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* Copyright (c) 1998 The NetBSD Foundation, Inc.
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@ -166,17 +166,6 @@ struct pv_head {
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"l3pt", \
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}
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struct pv_page_info {
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TAILQ_ENTRY(pv_page) pgi_list;
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LIST_HEAD(, pv_entry) pgi_freelist;
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int pgi_nfree;
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};
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struct pv_page {
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struct pv_page_info pvp_pgi;
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struct pv_entry pvp_pv[1]; /* variable length */
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};
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#ifdef _KERNEL
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#ifndef _LKM
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Reference in New Issue
Block a user