/* $NetBSD: uvm_page.c,v 1.256 2024/03/05 14:33:50 thorpej Exp $ */ /*- * Copyright (c) 2019, 2020 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Andrew Doran. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * Copyright (c) 1991, 1993, The Regents of the University of California. * * All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * uvm_page.c: page ops. */ #include __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.256 2024/03/05 14:33:50 thorpej Exp $"); #include "opt_ddb.h" #include "opt_uvm.h" #include "opt_uvmhist.h" #include "opt_readahead.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * number of pages per-CPU to reserve for the kernel. */ #ifndef UVM_RESERVED_PAGES_PER_CPU #define UVM_RESERVED_PAGES_PER_CPU 5 #endif int vm_page_reserve_kernel = UVM_RESERVED_PAGES_PER_CPU; /* * physical memory size; */ psize_t physmem; /* * local variables */ /* * these variables record the values returned by vm_page_bootstrap, * for debugging purposes. The implementation of uvm_pageboot_alloc * and pmap_startup here also uses them internally. */ static vaddr_t virtual_space_start; static vaddr_t virtual_space_end; /* * we allocate an initial number of page colors in uvm_page_init(), * and remember them. We may re-color pages as cache sizes are * discovered during the autoconfiguration phase. But we can never * free the initial set of buckets, since they are allocated using * uvm_pageboot_alloc(). */ static size_t recolored_pages_memsize /* = 0 */; static char *recolored_pages_mem; /* * freelist locks - one per bucket. */ union uvm_freelist_lock uvm_freelist_locks[PGFL_MAX_BUCKETS] __cacheline_aligned; /* * basic NUMA information. */ static struct uvm_page_numa_region { struct uvm_page_numa_region *next; paddr_t start; paddr_t size; u_int numa_id; } *uvm_page_numa_region; #ifdef DEBUG kmutex_t uvm_zerochecklock __cacheline_aligned; vaddr_t uvm_zerocheckkva; #endif /* DEBUG */ /* * These functions are reserved for uvm(9) internal use and are not * exported in the header file uvm_physseg.h * * Thus they are redefined here. */ void uvm_physseg_init_seg(uvm_physseg_t, struct vm_page *); void uvm_physseg_seg_chomp_slab(uvm_physseg_t, struct vm_page *, size_t); /* returns a pgs array */ struct vm_page *uvm_physseg_seg_alloc_from_slab(uvm_physseg_t, size_t); /* * inline functions */ /* * uvm_pageinsert: insert a page in the object. * * => caller must lock object * => call should have already set pg's object and offset pointers * and bumped the version counter */ static inline void uvm_pageinsert_object(struct uvm_object *uobj, struct vm_page *pg) { KASSERT(uobj == pg->uobject); KASSERT(rw_write_held(uobj->vmobjlock)); KASSERT((pg->flags & PG_TABLED) == 0); if ((pg->flags & PG_STAT) != 0) { /* Cannot use uvm_pagegetdirty(): not yet in radix tree. */ const unsigned int status = pg->flags & (PG_CLEAN | PG_DIRTY); if ((pg->flags & PG_FILE) != 0) { if (uobj->uo_npages == 0) { struct vnode *vp = (struct vnode *)uobj; mutex_enter(vp->v_interlock); KASSERT((vp->v_iflag & VI_PAGES) == 0); vp->v_iflag |= VI_PAGES; vholdl(vp); mutex_exit(vp->v_interlock); } if (UVM_OBJ_IS_VTEXT(uobj)) { cpu_count(CPU_COUNT_EXECPAGES, 1); } cpu_count(CPU_COUNT_FILEUNKNOWN + status, 1); } else { cpu_count(CPU_COUNT_ANONUNKNOWN + status, 1); } } pg->flags |= PG_TABLED; uobj->uo_npages++; } static inline int uvm_pageinsert_tree(struct uvm_object *uobj, struct vm_page *pg) { const uint64_t idx = pg->offset >> PAGE_SHIFT; int error; KASSERT(rw_write_held(uobj->vmobjlock)); error = radix_tree_insert_node(&uobj->uo_pages, idx, pg); if (error != 0) { return error; } if ((pg->flags & PG_CLEAN) == 0) { uvm_obj_page_set_dirty(pg); } KASSERT(((pg->flags & PG_CLEAN) == 0) == uvm_obj_page_dirty_p(pg)); return 0; } /* * uvm_page_remove: remove page from object. * * => caller must lock object */ static inline void uvm_pageremove_object(struct uvm_object *uobj, struct vm_page *pg) { KASSERT(uobj == pg->uobject); KASSERT(rw_write_held(uobj->vmobjlock)); KASSERT(pg->flags & PG_TABLED); if ((pg->flags & PG_STAT) != 0) { /* Cannot use uvm_pagegetdirty(): no longer in radix tree. */ const unsigned int status = pg->flags & (PG_CLEAN | PG_DIRTY); if ((pg->flags & PG_FILE) != 0) { if (uobj->uo_npages == 1) { struct vnode *vp = (struct vnode *)uobj; mutex_enter(vp->v_interlock); KASSERT((vp->v_iflag & VI_PAGES) != 0); vp->v_iflag &= ~VI_PAGES; holdrelel(vp); mutex_exit(vp->v_interlock); } if (UVM_OBJ_IS_VTEXT(uobj)) { cpu_count(CPU_COUNT_EXECPAGES, -1); } cpu_count(CPU_COUNT_FILEUNKNOWN + status, -1); } else { cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1); } } uobj->uo_npages--; pg->flags &= ~PG_TABLED; pg->uobject = NULL; } static inline void uvm_pageremove_tree(struct uvm_object *uobj, struct vm_page *pg) { struct vm_page *opg __unused; KASSERT(rw_write_held(uobj->vmobjlock)); opg = radix_tree_remove_node(&uobj->uo_pages, pg->offset >> PAGE_SHIFT); KASSERT(pg == opg); } static void uvm_page_init_bucket(struct pgfreelist *pgfl, struct pgflbucket *pgb, int num) { int i; pgb->pgb_nfree = 0; for (i = 0; i < uvmexp.ncolors; i++) { LIST_INIT(&pgb->pgb_colors[i]); } pgfl->pgfl_buckets[num] = pgb; } /* * uvm_page_init: init the page system. called from uvm_init(). * * => we return the range of kernel virtual memory in kvm_startp/kvm_endp */ void uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp) { static struct uvm_cpu uvm_boot_cpu __cacheline_aligned; psize_t freepages, pagecount, bucketsize, n; struct pgflbucket *pgb; struct vm_page *pagearray; char *bucketarray; uvm_physseg_t bank; int fl, b; KASSERT(ncpu <= 1); /* * init the page queues and free page queue locks, except the * free list; we allocate that later (with the initial vm_page * structures). */ curcpu()->ci_data.cpu_uvm = &uvm_boot_cpu; uvmpdpol_init(); for (b = 0; b < __arraycount(uvm_freelist_locks); b++) { mutex_init(&uvm_freelist_locks[b].lock, MUTEX_DEFAULT, IPL_VM); } /* * allocate vm_page structures. */ /* * sanity check: * before calling this function the MD code is expected to register * some free RAM with the uvm_page_physload() function. our job * now is to allocate vm_page structures for this memory. */ if (uvm_physseg_get_last() == UVM_PHYSSEG_TYPE_INVALID) panic("uvm_page_bootstrap: no memory pre-allocated"); /* * first calculate the number of free pages... * * note that we use start/end rather than avail_start/avail_end. * this allows us to allocate extra vm_page structures in case we * want to return some memory to the pool after booting. */ freepages = 0; for (bank = uvm_physseg_get_first(); uvm_physseg_valid_p(bank) ; bank = uvm_physseg_get_next(bank)) { freepages += (uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank)); } /* * Let MD code initialize the number of colors, or default * to 1 color if MD code doesn't care. */ if (uvmexp.ncolors == 0) uvmexp.ncolors = 1; uvmexp.colormask = uvmexp.ncolors - 1; KASSERT((uvmexp.colormask & uvmexp.ncolors) == 0); /* We always start with only 1 bucket. */ uvm.bucketcount = 1; /* * we now know we have (PAGE_SIZE * freepages) bytes of memory we can * use. for each page of memory we use we need a vm_page structure. * thus, the total number of pages we can use is the total size of * the memory divided by the PAGE_SIZE plus the size of the vm_page * structure. we add one to freepages as a fudge factor to avoid * truncation errors (since we can only allocate in terms of whole * pages). */ pagecount = ((freepages + 1) << PAGE_SHIFT) / (PAGE_SIZE + sizeof(struct vm_page)); bucketsize = offsetof(struct pgflbucket, pgb_colors[uvmexp.ncolors]); bucketsize = roundup2(bucketsize, coherency_unit); bucketarray = (void *)uvm_pageboot_alloc( bucketsize * VM_NFREELIST + pagecount * sizeof(struct vm_page)); pagearray = (struct vm_page *) (bucketarray + bucketsize * VM_NFREELIST); for (fl = 0; fl < VM_NFREELIST; fl++) { pgb = (struct pgflbucket *)(bucketarray + bucketsize * fl); uvm_page_init_bucket(&uvm.page_free[fl], pgb, 0); } memset(pagearray, 0, pagecount * sizeof(struct vm_page)); /* * init the freelist cache in the disabled state. */ uvm_pgflcache_init(); /* * init the vm_page structures and put them in the correct place. */ /* First init the extent */ for (bank = uvm_physseg_get_first(), uvm_physseg_seg_chomp_slab(bank, pagearray, pagecount); uvm_physseg_valid_p(bank); bank = uvm_physseg_get_next(bank)) { n = uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank); uvm_physseg_seg_alloc_from_slab(bank, n); uvm_physseg_init_seg(bank, pagearray); /* set up page array pointers */ pagearray += n; pagecount -= n; } /* * pass up the values of virtual_space_start and * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper * layers of the VM. */ *kvm_startp = round_page(virtual_space_start); *kvm_endp = trunc_page(virtual_space_end); /* * init various thresholds. */ uvmexp.reserve_pagedaemon = 1; uvmexp.reserve_kernel = vm_page_reserve_kernel; /* * done! */ uvm.page_init_done = true; } /* * uvm_pgfl_lock: lock all freelist buckets */ void uvm_pgfl_lock(void) { int i; for (i = 0; i < __arraycount(uvm_freelist_locks); i++) { mutex_spin_enter(&uvm_freelist_locks[i].lock); } } /* * uvm_pgfl_unlock: unlock all freelist buckets */ void uvm_pgfl_unlock(void) { int i; for (i = 0; i < __arraycount(uvm_freelist_locks); i++) { mutex_spin_exit(&uvm_freelist_locks[i].lock); } } /* * uvm_setpagesize: set the page size * * => sets page_shift and page_mask from uvmexp.pagesize. */ void uvm_setpagesize(void) { /* * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE * to be a constant (indicated by being a non-zero value). */ if (uvmexp.pagesize == 0) { if (PAGE_SIZE == 0) panic("uvm_setpagesize: uvmexp.pagesize not set"); uvmexp.pagesize = PAGE_SIZE; } uvmexp.pagemask = uvmexp.pagesize - 1; if ((uvmexp.pagemask & uvmexp.pagesize) != 0) panic("uvm_setpagesize: page size %u (%#x) not a power of two", uvmexp.pagesize, uvmexp.pagesize); for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) if ((1 << uvmexp.pageshift) == uvmexp.pagesize) break; } /* * uvm_pageboot_alloc: steal memory from physmem for bootstrapping */ vaddr_t uvm_pageboot_alloc(vsize_t size) { static bool initialized = false; vaddr_t addr; #if !defined(PMAP_STEAL_MEMORY) vaddr_t vaddr; paddr_t paddr; #endif /* * on first call to this function, initialize ourselves. */ if (initialized == false) { pmap_virtual_space(&virtual_space_start, &virtual_space_end); /* round it the way we like it */ virtual_space_start = round_page(virtual_space_start); virtual_space_end = trunc_page(virtual_space_end); initialized = true; } /* round to page size */ size = round_page(size); uvmexp.bootpages += atop(size); #if defined(PMAP_STEAL_MEMORY) /* * defer bootstrap allocation to MD code (it may want to allocate * from a direct-mapped segment). pmap_steal_memory should adjust * virtual_space_start/virtual_space_end if necessary. */ addr = pmap_steal_memory(size, &virtual_space_start, &virtual_space_end); return addr; #else /* !PMAP_STEAL_MEMORY */ /* * allocate virtual memory for this request */ if (virtual_space_start == virtual_space_end || (virtual_space_end - virtual_space_start) < size) panic("uvm_pageboot_alloc: out of virtual space"); addr = virtual_space_start; #ifdef PMAP_GROWKERNEL /* * If the kernel pmap can't map the requested space, * then allocate more resources for it. */ if (uvm_maxkaddr < (addr + size)) { uvm_maxkaddr = pmap_growkernel(addr + size); if (uvm_maxkaddr < (addr + size)) panic("uvm_pageboot_alloc: pmap_growkernel() failed"); } #endif virtual_space_start += size; /* * allocate and mapin physical pages to back new virtual pages */ for (vaddr = round_page(addr) ; vaddr < addr + size ; vaddr += PAGE_SIZE) { if (!uvm_page_physget(&paddr)) panic("uvm_pageboot_alloc: out of memory"); /* * Note this memory is no longer managed, so using * pmap_kenter is safe. */ pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE, 0); } pmap_update(pmap_kernel()); return addr; #endif /* PMAP_STEAL_MEMORY */ } #if !defined(PMAP_STEAL_MEMORY) /* * uvm_page_physget: "steal" one page from the vm_physmem structure. * * => attempt to allocate it off the end of a segment in which the "avail" * values match the start/end values. if we can't do that, then we * will advance both values (making them equal, and removing some * vm_page structures from the non-avail area). * => return false if out of memory. */ /* subroutine: try to allocate from memory chunks on the specified freelist */ static bool uvm_page_physget_freelist(paddr_t *, int); static bool uvm_page_physget_freelist(paddr_t *paddrp, int freelist) { uvm_physseg_t lcv; /* pass 1: try allocating from a matching end */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv)) #else for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv)) #endif { if (uvm.page_init_done == true) panic("uvm_page_physget: called _after_ bootstrap"); /* Try to match at front or back on unused segment */ if (uvm_page_physunload(lcv, freelist, paddrp)) return true; } /* pass2: forget about matching ends, just allocate something */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv)) #else for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv)) #endif { /* Try the front regardless. */ if (uvm_page_physunload_force(lcv, freelist, paddrp)) return true; } return false; } bool uvm_page_physget(paddr_t *paddrp) { int i; /* try in the order of freelist preference */ for (i = 0; i < VM_NFREELIST; i++) if (uvm_page_physget_freelist(paddrp, i) == true) return (true); return (false); } #endif /* PMAP_STEAL_MEMORY */ paddr_t uvm_vm_page_to_phys(const struct vm_page *pg) { return pg->phys_addr & ~(PAGE_SIZE - 1); } /* * uvm_page_numa_load: load NUMA range description. */ void uvm_page_numa_load(paddr_t start, paddr_t size, u_int numa_id) { struct uvm_page_numa_region *d; KASSERT(numa_id < PGFL_MAX_BUCKETS); d = kmem_alloc(sizeof(*d), KM_SLEEP); d->start = start; d->size = size; d->numa_id = numa_id; d->next = uvm_page_numa_region; uvm_page_numa_region = d; } /* * uvm_page_numa_lookup: lookup NUMA node for the given page. */ static u_int uvm_page_numa_lookup(struct vm_page *pg) { struct uvm_page_numa_region *d; static bool warned; paddr_t pa; KASSERT(uvm_page_numa_region != NULL); pa = VM_PAGE_TO_PHYS(pg); for (d = uvm_page_numa_region; d != NULL; d = d->next) { if (pa >= d->start && pa < d->start + d->size) { return d->numa_id; } } if (!warned) { printf("uvm_page_numa_lookup: failed, first pg=%p pa=%#" PRIxPADDR "\n", pg, VM_PAGE_TO_PHYS(pg)); warned = true; } return 0; } /* * uvm_page_redim: adjust freelist dimensions if they have changed. */ static void uvm_page_redim(int newncolors, int newnbuckets) { struct pgfreelist npgfl; struct pgflbucket *opgb, *npgb; struct pgflist *ohead, *nhead; struct vm_page *pg; size_t bucketsize, bucketmemsize, oldbucketmemsize; int fl, ob, oc, nb, nc, obuckets, ocolors; char *bucketarray, *oldbucketmem, *bucketmem; KASSERT(((newncolors - 1) & newncolors) == 0); /* Anything to do? */ if (newncolors <= uvmexp.ncolors && newnbuckets == uvm.bucketcount) { return; } if (uvm.page_init_done == false) { uvmexp.ncolors = newncolors; return; } bucketsize = offsetof(struct pgflbucket, pgb_colors[newncolors]); bucketsize = roundup2(bucketsize, coherency_unit); bucketmemsize = bucketsize * newnbuckets * VM_NFREELIST + coherency_unit - 1; bucketmem = kmem_zalloc(bucketmemsize, KM_SLEEP); bucketarray = (char *)roundup2((uintptr_t)bucketmem, coherency_unit); ocolors = uvmexp.ncolors; obuckets = uvm.bucketcount; /* Freelist cache mustn't be enabled. */ uvm_pgflcache_pause(); /* Make sure we should still do this. */ uvm_pgfl_lock(); if (newncolors <= uvmexp.ncolors && newnbuckets == uvm.bucketcount) { uvm_pgfl_unlock(); uvm_pgflcache_resume(); kmem_free(bucketmem, bucketmemsize); return; } uvmexp.ncolors = newncolors; uvmexp.colormask = uvmexp.ncolors - 1; uvm.bucketcount = newnbuckets; for (fl = 0; fl < VM_NFREELIST; fl++) { /* Init new buckets in new freelist. */ memset(&npgfl, 0, sizeof(npgfl)); for (nb = 0; nb < newnbuckets; nb++) { npgb = (struct pgflbucket *)bucketarray; uvm_page_init_bucket(&npgfl, npgb, nb); bucketarray += bucketsize; } /* Now transfer pages from the old freelist. */ for (nb = ob = 0; ob < obuckets; ob++) { opgb = uvm.page_free[fl].pgfl_buckets[ob]; for (oc = 0; oc < ocolors; oc++) { ohead = &opgb->pgb_colors[oc]; while ((pg = LIST_FIRST(ohead)) != NULL) { LIST_REMOVE(pg, pageq.list); /* * Here we decide on the NEW color & * bucket for the page. For NUMA * we'll use the info that the * hardware gave us. For non-NUMA * assign take physical page frame * number and cache color into * account. We do this to try and * avoid defeating any memory * interleaving in the hardware. */ KASSERT( uvm_page_get_bucket(pg) == ob); KASSERT(fl == uvm_page_get_freelist(pg)); if (uvm_page_numa_region != NULL) { nb = uvm_page_numa_lookup(pg); } else { nb = atop(VM_PAGE_TO_PHYS(pg)) / uvmexp.ncolors / 8 % newnbuckets; } uvm_page_set_bucket(pg, nb); npgb = npgfl.pgfl_buckets[nb]; npgb->pgb_nfree++; nc = VM_PGCOLOR(pg); nhead = &npgb->pgb_colors[nc]; LIST_INSERT_HEAD(nhead, pg, pageq.list); } } } /* Install the new freelist. */ memcpy(&uvm.page_free[fl], &npgfl, sizeof(npgfl)); } /* Unlock and free the old memory. */ oldbucketmemsize = recolored_pages_memsize; oldbucketmem = recolored_pages_mem; recolored_pages_memsize = bucketmemsize; recolored_pages_mem = bucketmem; uvm_pgfl_unlock(); uvm_pgflcache_resume(); if (oldbucketmemsize) { kmem_free(oldbucketmem, oldbucketmemsize); } /* * this calls uvm_km_alloc() which may want to hold * uvm_freelist_lock. */ uvm_pager_realloc_emerg(); } /* * uvm_page_recolor: Recolor the pages if the new color count is * larger than the old one. */ void uvm_page_recolor(int newncolors) { uvm_page_redim(newncolors, uvm.bucketcount); } /* * uvm_page_rebucket: Determine a bucket structure and redim the free * lists to match. */ void uvm_page_rebucket(void) { u_int min_numa, max_numa, npackage, shift; struct cpu_info *ci, *ci2, *ci3; CPU_INFO_ITERATOR cii; /* * If we have more than one NUMA node, and the maximum NUMA node ID * is less than PGFL_MAX_BUCKETS, then we'll use NUMA distribution * for free pages. */ min_numa = (u_int)-1; max_numa = 0; for (CPU_INFO_FOREACH(cii, ci)) { if (ci->ci_numa_id < min_numa) { min_numa = ci->ci_numa_id; } if (ci->ci_numa_id > max_numa) { max_numa = ci->ci_numa_id; } } if (min_numa != max_numa && max_numa < PGFL_MAX_BUCKETS) { aprint_debug("UVM: using NUMA allocation scheme\n"); for (CPU_INFO_FOREACH(cii, ci)) { ci->ci_data.cpu_uvm->pgflbucket = ci->ci_numa_id; } uvm_page_redim(uvmexp.ncolors, max_numa + 1); return; } /* * Otherwise we'll go with a scheme to maximise L2/L3 cache locality * and minimise lock contention. Count the total number of CPU * packages, and then try to distribute the buckets among CPU * packages evenly. */ npackage = curcpu()->ci_nsibling[CPUREL_PACKAGE1ST]; /* * Figure out how to arrange the packages & buckets, and the total * number of buckets we need. XXX 2 may not be the best factor. */ for (shift = 0; npackage > PGFL_MAX_BUCKETS; shift++) { npackage >>= 1; } uvm_page_redim(uvmexp.ncolors, npackage); /* * Now tell each CPU which bucket to use. In the outer loop, scroll * through all CPU packages. */ npackage = 0; ci = curcpu(); ci2 = ci->ci_sibling[CPUREL_PACKAGE1ST]; do { /* * In the inner loop, scroll through all CPUs in the package * and assign the same bucket ID. */ ci3 = ci2; do { ci3->ci_data.cpu_uvm->pgflbucket = npackage >> shift; ci3 = ci3->ci_sibling[CPUREL_PACKAGE]; } while (ci3 != ci2); npackage++; ci2 = ci2->ci_sibling[CPUREL_PACKAGE1ST]; } while (ci2 != ci->ci_sibling[CPUREL_PACKAGE1ST]); aprint_debug("UVM: using package allocation scheme, " "%d package(s) per bucket\n", 1 << shift); } /* * uvm_cpu_attach: initialize per-CPU data structures. */ void uvm_cpu_attach(struct cpu_info *ci) { struct uvm_cpu *ucpu; /* Already done in uvm_page_init(). */ if (!CPU_IS_PRIMARY(ci)) { /* Add more reserve pages for this CPU. */ uvmexp.reserve_kernel += vm_page_reserve_kernel; /* Allocate per-CPU data structures. */ ucpu = kmem_zalloc(sizeof(struct uvm_cpu) + coherency_unit - 1, KM_SLEEP); ucpu = (struct uvm_cpu *)roundup2((uintptr_t)ucpu, coherency_unit); ci->ci_data.cpu_uvm = ucpu; } else { ucpu = ci->ci_data.cpu_uvm; } uvmpdpol_init_cpu(ucpu); } /* * uvm_availmem: fetch the total amount of free memory in pages. this can * have a detrimental effect on performance due to false sharing; don't call * unless needed. * * some users can request the amount of free memory so often that it begins * to impact upon performance. if calling frequently and an inexact value * is okay, call with cached = true. */ int uvm_availmem(bool cached) { int64_t fp; cpu_count_sync(cached); if ((fp = cpu_count_get(CPU_COUNT_FREEPAGES)) < 0) { /* * XXXAD could briefly go negative because it's impossible * to get a clean snapshot. address this for other counters * used as running totals before NetBSD 10 although less * important for those. */ fp = 0; } return (int)fp; } /* * uvm_pagealloc_pgb: helper routine that tries to allocate any color from a * specific freelist and specific bucket only. * * => must be at IPL_VM or higher to protect per-CPU data structures. */ static struct vm_page * uvm_pagealloc_pgb(struct uvm_cpu *ucpu, int f, int b, int *trycolorp, int flags) { int c, trycolor, colormask; struct pgflbucket *pgb; struct vm_page *pg; kmutex_t *lock; bool fill; /* * Skip the bucket if empty, no lock needed. There could be many * empty freelists/buckets. */ pgb = uvm.page_free[f].pgfl_buckets[b]; if (pgb->pgb_nfree == 0) { return NULL; } /* Skip bucket if low on memory. */ lock = &uvm_freelist_locks[b].lock; mutex_spin_enter(lock); if (__predict_false(pgb->pgb_nfree <= uvmexp.reserve_kernel)) { if ((flags & UVM_PGA_USERESERVE) == 0 || (pgb->pgb_nfree <= uvmexp.reserve_pagedaemon && curlwp != uvm.pagedaemon_lwp)) { mutex_spin_exit(lock); return NULL; } fill = false; } else { fill = true; } /* Try all page colors as needed. */ c = trycolor = *trycolorp; colormask = uvmexp.colormask; do { pg = LIST_FIRST(&pgb->pgb_colors[c]); if (__predict_true(pg != NULL)) { /* * Got a free page! PG_FREE must be cleared under * lock because of uvm_pglistalloc(). */ LIST_REMOVE(pg, pageq.list); KASSERT(pg->flags == PG_FREE); pg->flags = PG_BUSY | PG_CLEAN | PG_FAKE; pgb->pgb_nfree--; CPU_COUNT(CPU_COUNT_FREEPAGES, -1); /* * While we have the bucket locked and our data * structures fresh in L1 cache, we have an ideal * opportunity to grab some pages for the freelist * cache without causing extra contention. Only do * so if we found pages in this CPU's preferred * bucket. */ if (__predict_true(b == ucpu->pgflbucket && fill)) { uvm_pgflcache_fill(ucpu, f, b, c); } mutex_spin_exit(lock); KASSERT(uvm_page_get_bucket(pg) == b); CPU_COUNT(c == trycolor ? CPU_COUNT_COLORHIT : CPU_COUNT_COLORMISS, 1); CPU_COUNT(CPU_COUNT_CPUMISS, 1); *trycolorp = c; return pg; } c = (c + 1) & colormask; } while (c != trycolor); mutex_spin_exit(lock); return NULL; } /* * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat that allocates * any color from any bucket, in a specific freelist. * * => must be at IPL_VM or higher to protect per-CPU data structures. */ static struct vm_page * uvm_pagealloc_pgfl(struct uvm_cpu *ucpu, int f, int *trycolorp, int flags) { int b, trybucket, bucketcount; struct vm_page *pg; /* Try for the exact thing in the per-CPU cache. */ if ((pg = uvm_pgflcache_alloc(ucpu, f, *trycolorp)) != NULL) { CPU_COUNT(CPU_COUNT_CPUHIT, 1); CPU_COUNT(CPU_COUNT_COLORHIT, 1); return pg; } /* Walk through all buckets, trying our preferred bucket first. */ trybucket = ucpu->pgflbucket; b = trybucket; bucketcount = uvm.bucketcount; do { pg = uvm_pagealloc_pgb(ucpu, f, b, trycolorp, flags); if (pg != NULL) { return pg; } b = (b + 1 == bucketcount ? 0 : b + 1); } while (b != trybucket); return NULL; } /* * uvm_pagealloc_strat: allocate vm_page from a particular free list. * * => return null if no pages free * => wake up pagedaemon if number of free pages drops below low water mark * => if obj != NULL, obj must be locked (to put in obj's tree) * => if anon != NULL, anon must be locked (to put in anon) * => only one of obj or anon can be non-null * => caller must activate/deactivate page if it is not wired. * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. * => policy decision: it is more important to pull a page off of the * appropriate priority free list than it is to get a page from the * correct bucket or color bin. This is because we live with the * consequences of a bad free list decision for the entire * lifetime of the page, e.g. if the page comes from memory that * is slower to access. */ struct vm_page * uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon, int flags, int strat, int free_list) { int color, lcv, error, s; struct uvm_cpu *ucpu; struct vm_page *pg; lwp_t *l; KASSERT(obj == NULL || anon == NULL); KASSERT(anon == NULL || (flags & UVM_FLAG_COLORMATCH) || off == 0); KASSERT(off == trunc_page(off)); KASSERT(obj == NULL || rw_write_held(obj->vmobjlock)); KASSERT(anon == NULL || anon->an_lock == NULL || rw_write_held(anon->an_lock)); /* * This implements a global round-robin page coloring * algorithm. */ s = splvm(); ucpu = curcpu()->ci_data.cpu_uvm; if (flags & UVM_FLAG_COLORMATCH) { color = atop(off) & uvmexp.colormask; } else { color = ucpu->pgflcolor; } /* * fail if any of these conditions is true: * [1] there really are no free pages, or * [2] only kernel "reserved" pages remain and * reserved pages have not been requested. * [3] only pagedaemon "reserved" pages remain and * the requestor isn't the pagedaemon. * we make kernel reserve pages available if called by a * kernel thread. */ l = curlwp; if (__predict_true(l != NULL) && (l->l_flag & LW_SYSTEM) != 0) { flags |= UVM_PGA_USERESERVE; } again: switch (strat) { case UVM_PGA_STRAT_NORMAL: /* Check freelists: descending priority (ascending id) order. */ for (lcv = 0; lcv < VM_NFREELIST; lcv++) { pg = uvm_pagealloc_pgfl(ucpu, lcv, &color, flags); if (pg != NULL) { goto gotit; } } /* No pages free! Have pagedaemon free some memory. */ splx(s); uvm_kick_pdaemon(); return NULL; case UVM_PGA_STRAT_ONLY: case UVM_PGA_STRAT_FALLBACK: /* Attempt to allocate from the specified free list. */ KASSERT(free_list >= 0); KASSERT(free_list < VM_NFREELIST); pg = uvm_pagealloc_pgfl(ucpu, free_list, &color, flags); if (pg != NULL) { goto gotit; } /* Fall back, if possible. */ if (strat == UVM_PGA_STRAT_FALLBACK) { strat = UVM_PGA_STRAT_NORMAL; goto again; } /* No pages free! Have pagedaemon free some memory. */ splx(s); uvm_kick_pdaemon(); return NULL; case UVM_PGA_STRAT_NUMA: /* * NUMA strategy (experimental): allocating from the correct * bucket is more important than observing freelist * priority. Look only to the current NUMA node; if that * fails, we need to look to other NUMA nodes, so retry with * the normal strategy. */ for (lcv = 0; lcv < VM_NFREELIST; lcv++) { pg = uvm_pgflcache_alloc(ucpu, lcv, color); if (pg != NULL) { CPU_COUNT(CPU_COUNT_CPUHIT, 1); CPU_COUNT(CPU_COUNT_COLORHIT, 1); goto gotit; } pg = uvm_pagealloc_pgb(ucpu, lcv, ucpu->pgflbucket, &color, flags); if (pg != NULL) { goto gotit; } } strat = UVM_PGA_STRAT_NORMAL; goto again; default: panic("uvm_pagealloc_strat: bad strat %d", strat); /* NOTREACHED */ } gotit: /* * We now know which color we actually allocated from; set * the next color accordingly. */ ucpu->pgflcolor = (color + 1) & uvmexp.colormask; /* * while still at IPL_VM, update allocation statistics. */ if (anon) { CPU_COUNT(CPU_COUNT_ANONCLEAN, 1); } splx(s); KASSERT(pg->flags == (PG_BUSY|PG_CLEAN|PG_FAKE)); /* * assign the page to the object. as the page was free, we know * that pg->uobject and pg->uanon are NULL. we only need to take * the page's interlock if we are changing the values. */ if (anon != NULL || obj != NULL) { mutex_enter(&pg->interlock); } pg->offset = off; pg->uobject = obj; pg->uanon = anon; KASSERT(uvm_page_owner_locked_p(pg, true)); if (anon) { anon->an_page = pg; pg->flags |= PG_ANON; mutex_exit(&pg->interlock); } else if (obj) { /* * set PG_FILE|PG_AOBJ before the first uvm_pageinsert. */ if (UVM_OBJ_IS_VNODE(obj)) { pg->flags |= PG_FILE; } else if (UVM_OBJ_IS_AOBJ(obj)) { pg->flags |= PG_AOBJ; } uvm_pageinsert_object(obj, pg); mutex_exit(&pg->interlock); error = uvm_pageinsert_tree(obj, pg); if (error != 0) { mutex_enter(&pg->interlock); uvm_pageremove_object(obj, pg); mutex_exit(&pg->interlock); uvm_pagefree(pg); return NULL; } } #if defined(UVM_PAGE_TRKOWN) pg->owner_tag = NULL; #endif UVM_PAGE_OWN(pg, "new alloc"); if (flags & UVM_PGA_ZERO) { /* A zero'd page is not clean. */ if (obj != NULL || anon != NULL) { uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); } pmap_zero_page(VM_PAGE_TO_PHYS(pg)); } return(pg); } /* * uvm_pagereplace: replace a page with another * * => object must be locked * => page interlocks must be held */ void uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg) { struct uvm_object *uobj = oldpg->uobject; struct vm_page *pg __diagused; uint64_t idx; KASSERT((oldpg->flags & PG_TABLED) != 0); KASSERT(uobj != NULL); KASSERT((newpg->flags & PG_TABLED) == 0); KASSERT(newpg->uobject == NULL); KASSERT(rw_write_held(uobj->vmobjlock)); KASSERT(mutex_owned(&oldpg->interlock)); KASSERT(mutex_owned(&newpg->interlock)); newpg->uobject = uobj; newpg->offset = oldpg->offset; idx = newpg->offset >> PAGE_SHIFT; pg = radix_tree_replace_node(&uobj->uo_pages, idx, newpg); KASSERT(pg == oldpg); if (((oldpg->flags ^ newpg->flags) & PG_CLEAN) != 0) { if ((newpg->flags & PG_CLEAN) != 0) { uvm_obj_page_clear_dirty(newpg); } else { uvm_obj_page_set_dirty(newpg); } } /* * oldpg's PG_STAT is stable. newpg is not reachable by others yet. */ newpg->flags |= (newpg->flags & ~PG_STAT) | (oldpg->flags & PG_STAT); uvm_pageinsert_object(uobj, newpg); uvm_pageremove_object(uobj, oldpg); } /* * uvm_pagerealloc: reallocate a page from one object to another * * => both objects must be locked */ int uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) { int error = 0; /* * remove it from the old object */ if (pg->uobject) { uvm_pageremove_tree(pg->uobject, pg); uvm_pageremove_object(pg->uobject, pg); } /* * put it in the new object */ if (newobj) { mutex_enter(&pg->interlock); pg->uobject = newobj; pg->offset = newoff; if (UVM_OBJ_IS_VNODE(newobj)) { pg->flags |= PG_FILE; } else if (UVM_OBJ_IS_AOBJ(newobj)) { pg->flags |= PG_AOBJ; } uvm_pageinsert_object(newobj, pg); mutex_exit(&pg->interlock); error = uvm_pageinsert_tree(newobj, pg); if (error != 0) { mutex_enter(&pg->interlock); uvm_pageremove_object(newobj, pg); mutex_exit(&pg->interlock); } } return error; } /* * uvm_pagefree: free page * * => erase page's identity (i.e. remove from object) * => put page on free list * => caller must lock owning object (either anon or uvm_object) * => assumes all valid mappings of pg are gone */ void uvm_pagefree(struct vm_page *pg) { struct pgfreelist *pgfl; struct pgflbucket *pgb; struct uvm_cpu *ucpu; kmutex_t *lock; int bucket, s; bool locked; #ifdef DEBUG if (pg->uobject == (void *)0xdeadbeef && pg->uanon == (void *)0xdeadbeef) { panic("uvm_pagefree: freeing free page %p", pg); } #endif /* DEBUG */ KASSERT((pg->flags & PG_PAGEOUT) == 0); KASSERT(!(pg->flags & PG_FREE)); KASSERT(pg->uobject == NULL || rw_write_held(pg->uobject->vmobjlock)); KASSERT(pg->uobject != NULL || pg->uanon == NULL || rw_write_held(pg->uanon->an_lock)); /* * remove the page from the object's tree before acquiring any page * interlocks: this can acquire locks to free radixtree nodes. */ if (pg->uobject != NULL) { uvm_pageremove_tree(pg->uobject, pg); } /* * if the page is loaned, resolve the loan instead of freeing. */ if (pg->loan_count) { KASSERT(pg->wire_count == 0); /* * if the page is owned by an anon then we just want to * drop anon ownership. the kernel will free the page when * it is done with it. if the page is owned by an object, * remove it from the object and mark it dirty for the benefit * of possible anon owners. * * regardless of previous ownership, wakeup any waiters, * unbusy the page, and we're done. */ uvm_pagelock(pg); locked = true; if (pg->uobject != NULL) { uvm_pageremove_object(pg->uobject, pg); pg->flags &= ~(PG_FILE|PG_AOBJ); } else if (pg->uanon != NULL) { if ((pg->flags & PG_ANON) == 0) { pg->loan_count--; } else { const unsigned status = uvm_pagegetdirty(pg); pg->flags &= ~PG_ANON; cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1); } pg->uanon->an_page = NULL; pg->uanon = NULL; } if (pg->pqflags & PQ_WANTED) { wakeup(pg); } pg->pqflags &= ~PQ_WANTED; pg->flags &= ~(PG_BUSY|PG_RELEASED|PG_PAGER1); #ifdef UVM_PAGE_TRKOWN pg->owner_tag = NULL; #endif KASSERT((pg->flags & PG_STAT) == 0); if (pg->loan_count) { KASSERT(pg->uobject == NULL); if (pg->uanon == NULL) { uvm_pagedequeue(pg); } uvm_pageunlock(pg); return; } } else if (pg->uobject != NULL || pg->uanon != NULL || pg->wire_count != 0) { uvm_pagelock(pg); locked = true; } else { locked = false; } /* * remove page from its object or anon. */ if (pg->uobject != NULL) { uvm_pageremove_object(pg->uobject, pg); } else if (pg->uanon != NULL) { const unsigned int status = uvm_pagegetdirty(pg); pg->uanon->an_page = NULL; pg->uanon = NULL; cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1); } /* * if the page was wired, unwire it now. */ if (pg->wire_count) { pg->wire_count = 0; atomic_dec_uint(&uvmexp.wired); } if (locked) { /* * wake anyone waiting on the page. */ if ((pg->pqflags & PQ_WANTED) != 0) { pg->pqflags &= ~PQ_WANTED; wakeup(pg); } /* * now remove the page from the queues. */ uvm_pagedequeue(pg); uvm_pageunlock(pg); } else { KASSERT(!uvmpdpol_pageisqueued_p(pg)); } /* * and put on free queue */ #ifdef DEBUG pg->uobject = (void *)0xdeadbeef; pg->uanon = (void *)0xdeadbeef; #endif /* DEBUG */ /* Try to send the page to the per-CPU cache. */ s = splvm(); ucpu = curcpu()->ci_data.cpu_uvm; bucket = uvm_page_get_bucket(pg); if (bucket == ucpu->pgflbucket && uvm_pgflcache_free(ucpu, pg)) { splx(s); return; } /* Didn't work. Never mind, send it to a global bucket. */ pgfl = &uvm.page_free[uvm_page_get_freelist(pg)]; pgb = pgfl->pgfl_buckets[bucket]; lock = &uvm_freelist_locks[bucket].lock; mutex_spin_enter(lock); /* PG_FREE must be set under lock because of uvm_pglistalloc(). */ pg->flags = PG_FREE; LIST_INSERT_HEAD(&pgb->pgb_colors[VM_PGCOLOR(pg)], pg, pageq.list); pgb->pgb_nfree++; CPU_COUNT(CPU_COUNT_FREEPAGES, 1); mutex_spin_exit(lock); splx(s); } /* * uvm_page_unbusy: unbusy an array of pages. * * => pages must either all belong to the same object, or all belong to anons. * => if pages are object-owned, object must be locked. * => if pages are anon-owned, anons must be locked. * => caller must make sure that anon-owned pages are not PG_RELEASED. */ void uvm_page_unbusy(struct vm_page **pgs, int npgs) { struct vm_page *pg; int i, pageout_done; UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); pageout_done = 0; for (i = 0; i < npgs; i++) { pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) { continue; } KASSERT(uvm_page_owner_locked_p(pg, true)); KASSERT(pg->flags & PG_BUSY); if (pg->flags & PG_PAGEOUT) { pg->flags &= ~PG_PAGEOUT; pg->flags |= PG_RELEASED; pageout_done++; atomic_inc_uint(&uvmexp.pdfreed); } if (pg->flags & PG_RELEASED) { UVMHIST_LOG(ubchist, "releasing pg %#jx", (uintptr_t)pg, 0, 0, 0); KASSERT(pg->uobject != NULL || (pg->uanon != NULL && pg->uanon->an_ref > 0)); pg->flags &= ~PG_RELEASED; uvm_pagefree(pg); } else { UVMHIST_LOG(ubchist, "unbusying pg %#jx", (uintptr_t)pg, 0, 0, 0); KASSERT((pg->flags & PG_FAKE) == 0); pg->flags &= ~PG_BUSY; uvm_pagelock(pg); uvm_pagewakeup(pg); uvm_pageunlock(pg); UVM_PAGE_OWN(pg, NULL); } } if (pageout_done != 0) { uvm_pageout_done(pageout_done); } } /* * uvm_pagewait: wait for a busy page * * => page must be known PG_BUSY * => object must be read or write locked * => object will be unlocked on return */ void uvm_pagewait(struct vm_page *pg, krwlock_t *lock, const char *wmesg) { KASSERT(rw_lock_held(lock)); KASSERT((pg->flags & PG_BUSY) != 0); KASSERT(uvm_page_owner_locked_p(pg, false)); mutex_enter(&pg->interlock); pg->pqflags |= PQ_WANTED; rw_exit(lock); UVM_UNLOCK_AND_WAIT(pg, &pg->interlock, false, wmesg, 0); } /* * uvm_pagewakeup: wake anyone waiting on a page * * => page interlock must be held */ void uvm_pagewakeup(struct vm_page *pg) { UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); KASSERT(mutex_owned(&pg->interlock)); UVMHIST_LOG(ubchist, "waking pg %#jx", (uintptr_t)pg, 0, 0, 0); if ((pg->pqflags & PQ_WANTED) != 0) { wakeup(pg); pg->pqflags &= ~PQ_WANTED; } } /* * uvm_pagewanted_p: return true if someone is waiting on the page * * => object must be write locked (lock out all concurrent access) */ bool uvm_pagewanted_p(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, true)); return (atomic_load_relaxed(&pg->pqflags) & PQ_WANTED) != 0; } #if defined(UVM_PAGE_TRKOWN) /* * uvm_page_own: set or release page ownership * * => this is a debugging function that keeps track of who sets PG_BUSY * and where they do it. it can be used to track down problems * such a process setting "PG_BUSY" and never releasing it. * => page's object [if any] must be locked * => if "tag" is NULL then we are releasing page ownership */ void uvm_page_own(struct vm_page *pg, const char *tag) { KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); KASSERT(uvm_page_owner_locked_p(pg, true)); /* gain ownership? */ if (tag) { KASSERT((pg->flags & PG_BUSY) != 0); if (pg->owner_tag) { printf("uvm_page_own: page %p already owned " "by proc %d.%d [%s]\n", pg, pg->owner, pg->lowner, pg->owner_tag); panic("uvm_page_own"); } pg->owner = curproc->p_pid; pg->lowner = curlwp->l_lid; pg->owner_tag = tag; return; } /* drop ownership */ KASSERT((pg->flags & PG_BUSY) == 0); if (pg->owner_tag == NULL) { printf("uvm_page_own: dropping ownership of an non-owned " "page (%p)\n", pg); panic("uvm_page_own"); } pg->owner_tag = NULL; } #endif /* * uvm_pagelookup: look up a page * * => caller should lock object to keep someone from pulling the page * out from under it */ struct vm_page * uvm_pagelookup(struct uvm_object *obj, voff_t off) { struct vm_page *pg; KASSERT(db_active || rw_lock_held(obj->vmobjlock)); pg = radix_tree_lookup_node(&obj->uo_pages, off >> PAGE_SHIFT); KASSERT(pg == NULL || obj->uo_npages != 0); KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || (pg->flags & PG_BUSY) != 0); return pg; } /* * uvm_pagewire: wire the page, thus removing it from the daemon's grasp * * => caller must lock objects * => caller must hold pg->interlock */ void uvm_pagewire(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, true)); KASSERT(mutex_owned(&pg->interlock)); #if defined(READAHEAD_STATS) if ((pg->flags & PG_READAHEAD) != 0) { uvm_ra_hit.ev_count++; pg->flags &= ~PG_READAHEAD; } #endif /* defined(READAHEAD_STATS) */ if (pg->wire_count == 0) { uvm_pagedequeue(pg); atomic_inc_uint(&uvmexp.wired); } pg->wire_count++; KASSERT(pg->wire_count > 0); /* detect wraparound */ } /* * uvm_pageunwire: unwire the page. * * => activate if wire count goes to zero. * => caller must lock objects * => caller must hold pg->interlock */ void uvm_pageunwire(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, true)); KASSERT(pg->wire_count != 0); KASSERT(!uvmpdpol_pageisqueued_p(pg)); KASSERT(mutex_owned(&pg->interlock)); pg->wire_count--; if (pg->wire_count == 0) { uvm_pageactivate(pg); KASSERT(uvmexp.wired != 0); atomic_dec_uint(&uvmexp.wired); } } /* * uvm_pagedeactivate: deactivate page * * => caller must lock objects * => caller must check to make sure page is not wired * => object that page belongs to must be locked (so we can adjust pg->flags) * => caller must clear the reference on the page before calling * => caller must hold pg->interlock */ void uvm_pagedeactivate(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, false)); KASSERT(mutex_owned(&pg->interlock)); if (pg->wire_count == 0) { KASSERT(uvmpdpol_pageisqueued_p(pg)); uvmpdpol_pagedeactivate(pg); } } /* * uvm_pageactivate: activate page * * => caller must lock objects * => caller must hold pg->interlock */ void uvm_pageactivate(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, false)); KASSERT(mutex_owned(&pg->interlock)); #if defined(READAHEAD_STATS) if ((pg->flags & PG_READAHEAD) != 0) { uvm_ra_hit.ev_count++; pg->flags &= ~PG_READAHEAD; } #endif /* defined(READAHEAD_STATS) */ if (pg->wire_count == 0) { uvmpdpol_pageactivate(pg); } } /* * uvm_pagedequeue: remove a page from any paging queue * * => caller must lock objects * => caller must hold pg->interlock */ void uvm_pagedequeue(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, true)); KASSERT(mutex_owned(&pg->interlock)); if (uvmpdpol_pageisqueued_p(pg)) { uvmpdpol_pagedequeue(pg); } } /* * uvm_pageenqueue: add a page to a paging queue without activating. * used where a page is not really demanded (yet). eg. read-ahead * * => caller must lock objects * => caller must hold pg->interlock */ void uvm_pageenqueue(struct vm_page *pg) { KASSERT(uvm_page_owner_locked_p(pg, false)); KASSERT(mutex_owned(&pg->interlock)); if (pg->wire_count == 0 && !uvmpdpol_pageisqueued_p(pg)) { uvmpdpol_pageenqueue(pg); } } /* * uvm_pagelock: acquire page interlock */ void uvm_pagelock(struct vm_page *pg) { mutex_enter(&pg->interlock); } /* * uvm_pagelock2: acquire two page interlocks */ void uvm_pagelock2(struct vm_page *pg1, struct vm_page *pg2) { if (pg1 < pg2) { mutex_enter(&pg1->interlock); mutex_enter(&pg2->interlock); } else { mutex_enter(&pg2->interlock); mutex_enter(&pg1->interlock); } } /* * uvm_pageunlock: release page interlock, and if a page replacement intent * is set on the page, pass it to uvmpdpol to make real. * * => caller must hold pg->interlock */ void uvm_pageunlock(struct vm_page *pg) { if ((pg->pqflags & PQ_INTENT_SET) == 0 || (pg->pqflags & PQ_INTENT_QUEUED) != 0) { mutex_exit(&pg->interlock); return; } pg->pqflags |= PQ_INTENT_QUEUED; mutex_exit(&pg->interlock); uvmpdpol_pagerealize(pg); } /* * uvm_pageunlock2: release two page interlocks, and for both pages if a * page replacement intent is set on the page, pass it to uvmpdpol to make * real. * * => caller must hold pg->interlock */ void uvm_pageunlock2(struct vm_page *pg1, struct vm_page *pg2) { if ((pg1->pqflags & PQ_INTENT_SET) == 0 || (pg1->pqflags & PQ_INTENT_QUEUED) != 0) { mutex_exit(&pg1->interlock); pg1 = NULL; } else { pg1->pqflags |= PQ_INTENT_QUEUED; mutex_exit(&pg1->interlock); } if ((pg2->pqflags & PQ_INTENT_SET) == 0 || (pg2->pqflags & PQ_INTENT_QUEUED) != 0) { mutex_exit(&pg2->interlock); pg2 = NULL; } else { pg2->pqflags |= PQ_INTENT_QUEUED; mutex_exit(&pg2->interlock); } if (pg1 != NULL) { uvmpdpol_pagerealize(pg1); } if (pg2 != NULL) { uvmpdpol_pagerealize(pg2); } } /* * uvm_pagezero: zero fill a page * * => if page is part of an object then the object should be locked * to protect pg->flags. */ void uvm_pagezero(struct vm_page *pg) { uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); pmap_zero_page(VM_PAGE_TO_PHYS(pg)); } /* * uvm_pagecopy: copy a page * * => if page is part of an object then the object should be locked * to protect pg->flags. */ void uvm_pagecopy(struct vm_page *src, struct vm_page *dst) { uvm_pagemarkdirty(dst, UVM_PAGE_STATUS_DIRTY); pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst)); } /* * uvm_pageismanaged: test it see that a page (specified by PA) is managed. */ bool uvm_pageismanaged(paddr_t pa) { return (uvm_physseg_find(atop(pa), NULL) != UVM_PHYSSEG_TYPE_INVALID); } /* * uvm_page_lookup_freelist: look up the free list for the specified page */ int uvm_page_lookup_freelist(struct vm_page *pg) { uvm_physseg_t upm; upm = uvm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL); KASSERT(upm != UVM_PHYSSEG_TYPE_INVALID); return uvm_physseg_get_free_list(upm); } /* * uvm_page_owner_locked_p: return true if object associated with page is * locked. this is a weak check for runtime assertions only. */ bool uvm_page_owner_locked_p(struct vm_page *pg, bool exclusive) { if (pg->uobject != NULL) { return exclusive ? rw_write_held(pg->uobject->vmobjlock) : rw_lock_held(pg->uobject->vmobjlock); } if (pg->uanon != NULL) { return exclusive ? rw_write_held(pg->uanon->an_lock) : rw_lock_held(pg->uanon->an_lock); } return true; } /* * uvm_pagereadonly_p: return if the page should be mapped read-only */ bool uvm_pagereadonly_p(struct vm_page *pg) { struct uvm_object * const uobj = pg->uobject; KASSERT(uobj == NULL || rw_lock_held(uobj->vmobjlock)); KASSERT(uobj != NULL || rw_lock_held(pg->uanon->an_lock)); if ((pg->flags & PG_RDONLY) != 0) { return true; } if (uvm_pagegetdirty(pg) == UVM_PAGE_STATUS_CLEAN) { return true; } if (uobj == NULL) { return false; } return UVM_OBJ_NEEDS_WRITEFAULT(uobj); } #ifdef PMAP_DIRECT /* * Call pmap to translate physical address into a virtual and to run a callback * for it. Used to avoid actually mapping the pages, pmap most likely uses direct map * or equivalent. */ int uvm_direct_process(struct vm_page **pgs, u_int npages, voff_t off, vsize_t len, int (*process)(void *, size_t, void *), void *arg) { int error = 0; paddr_t pa; size_t todo; voff_t pgoff = (off & PAGE_MASK); struct vm_page *pg; KASSERT(npages > 0); KASSERT(len > 0); for (int i = 0; i < npages; i++) { pg = pgs[i]; KASSERT(len > 0); /* * Caller is responsible for ensuring all the pages are * available. */ KASSERT(pg != NULL); KASSERT(pg != PGO_DONTCARE); pa = VM_PAGE_TO_PHYS(pg); todo = MIN(len, PAGE_SIZE - pgoff); error = pmap_direct_process(pa, pgoff, todo, process, arg); if (error) break; pgoff = 0; len -= todo; } KASSERTMSG(error != 0 || len == 0, "len %lu != 0 for non-error", len); return error; } #endif /* PMAP_DIRECT */ #if defined(DDB) || defined(DEBUGPRINT) /* * uvm_page_printit: actually print the page */ static const char page_flagbits[] = UVM_PGFLAGBITS; static const char page_pqflagbits[] = UVM_PQFLAGBITS; void uvm_page_printit(struct vm_page *pg, bool full, void (*pr)(const char *, ...)) { struct vm_page *tpg; struct uvm_object *uobj; struct pgflbucket *pgb; struct pgflist *pgl; char pgbuf[128]; (*pr)("PAGE %p:\n", pg); snprintb(pgbuf, sizeof(pgbuf), page_flagbits, pg->flags); (*pr)(" flags=%s\n", pgbuf); snprintb(pgbuf, sizeof(pgbuf), page_pqflagbits, pg->pqflags); (*pr)(" pqflags=%s\n", pgbuf); (*pr)(" uobject=%p, uanon=%p, offset=0x%llx\n", pg->uobject, pg->uanon, (long long)pg->offset); (*pr)(" loan_count=%d wire_count=%d bucket=%d freelist=%d\n", pg->loan_count, pg->wire_count, uvm_page_get_bucket(pg), uvm_page_get_freelist(pg)); (*pr)(" pa=0x%lx\n", (long)VM_PAGE_TO_PHYS(pg)); #if defined(UVM_PAGE_TRKOWN) if (pg->flags & PG_BUSY) (*pr)(" owning process = %d.%d, tag=%s\n", pg->owner, pg->lowner, pg->owner_tag); else (*pr)(" page not busy, no owner\n"); #else (*pr)(" [page ownership tracking disabled]\n"); #endif if (!full) return; /* cross-verify object/anon */ if ((pg->flags & PG_FREE) == 0) { if (pg->flags & PG_ANON) { if (pg->uanon == NULL || pg->uanon->an_page != pg) (*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n", (pg->uanon) ? pg->uanon->an_page : NULL); else (*pr)(" anon backpointer is OK\n"); } else { uobj = pg->uobject; if (uobj) { (*pr)(" checking object list\n"); tpg = uvm_pagelookup(uobj, pg->offset); if (tpg) (*pr)(" page found on object list\n"); else (*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n"); } } } /* cross-verify page queue */ if (pg->flags & PG_FREE) { int fl = uvm_page_get_freelist(pg); int b = uvm_page_get_bucket(pg); pgb = uvm.page_free[fl].pgfl_buckets[b]; pgl = &pgb->pgb_colors[VM_PGCOLOR(pg)]; (*pr)(" checking pageq list\n"); LIST_FOREACH(tpg, pgl, pageq.list) { if (tpg == pg) { break; } } if (tpg) (*pr)(" page found on pageq list\n"); else (*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n"); } } /* * uvm_page_printall - print a summary of all managed pages */ void uvm_page_printall(void (*pr)(const char *, ...)) { uvm_physseg_t i; paddr_t pfn; struct vm_page *pg; (*pr)("%18s %4s %4s %18s %18s" #ifdef UVM_PAGE_TRKOWN " OWNER" #endif "\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON"); for (i = uvm_physseg_get_first(); uvm_physseg_valid_p(i); i = uvm_physseg_get_next(i)) { for (pfn = uvm_physseg_get_start(i); pfn < uvm_physseg_get_end(i); pfn++) { pg = PHYS_TO_VM_PAGE(ptoa(pfn)); (*pr)("%18p %04x %08x %18p %18p", pg, pg->flags, pg->pqflags, pg->uobject, pg->uanon); #ifdef UVM_PAGE_TRKOWN if (pg->flags & PG_BUSY) (*pr)(" %d [%s]", pg->owner, pg->owner_tag); #endif (*pr)("\n"); } } } /* * uvm_page_print_freelists - print a summary freelists */ void uvm_page_print_freelists(void (*pr)(const char *, ...)) { struct pgfreelist *pgfl; struct pgflbucket *pgb; int fl, b, c; (*pr)("There are %d freelists with %d buckets of %d colors.\n\n", VM_NFREELIST, uvm.bucketcount, uvmexp.ncolors); for (fl = 0; fl < VM_NFREELIST; fl++) { pgfl = &uvm.page_free[fl]; (*pr)("freelist(%d) @ %p\n", fl, pgfl); for (b = 0; b < uvm.bucketcount; b++) { pgb = uvm.page_free[fl].pgfl_buckets[b]; (*pr)(" bucket(%d) @ %p, nfree = %d, lock @ %p:\n", b, pgb, pgb->pgb_nfree, &uvm_freelist_locks[b].lock); for (c = 0; c < uvmexp.ncolors; c++) { (*pr)(" color(%d) @ %p, ", c, &pgb->pgb_colors[c]); (*pr)("first page = %p\n", LIST_FIRST(&pgb->pgb_colors[c])); } } } } #endif /* DDB || DEBUGPRINT */