FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_pagequeue.h

     /*-
      * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
      *
      * 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.
     *
     *      from: @(#)vm_page.h     8.2 (Berkeley) 12/13/93
     *
     *
     * Copyright (c) 1987, 1990 Carnegie-Mellon University.
     * All rights reserved.
     *
     * Authors: Avadis Tevanian, Jr., Michael Wayne Young
     *
     * 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.
     *
     * $FreeBSD: releng/12.0/sys/vm/vm_pagequeue.h 339043 2018-10-01 14:14:21Z gallatin $
     */
    
    #ifndef _VM_PAGEQUEUE_
    #define _VM_PAGEQUEUE_
    
    #ifdef _KERNEL
    struct vm_pagequeue {
            struct mtx      pq_mutex;
            struct pglist   pq_pl;
            int             pq_cnt;
            const char      * const pq_name;
            uint64_t        pq_pdpages;
    } __aligned(CACHE_LINE_SIZE);
    
    #ifndef VM_BATCHQUEUE_SIZE
    #define VM_BATCHQUEUE_SIZE      7
    #endif
    
    struct vm_batchqueue {
            vm_page_t       bq_pa[VM_BATCHQUEUE_SIZE];
            int             bq_cnt;
    } __aligned(CACHE_LINE_SIZE);
    
    #include <vm/uma.h>
    #include <sys/pidctrl.h>
    struct sysctl_oid;
    
    /*
     * One vm_domain per-numa domain.  Contains pagequeues, free page structures,
     * and accounting.
     *
     * Lock Key:
     * f    vmd_free_mtx
     * p    vmd_pageout_mtx
     * d    vm_domainset_lock
     * a    atomic
     * c    const after boot
    * q    page queue lock
   */
   struct vm_domain {
           struct vm_pagequeue vmd_pagequeues[PQ_COUNT];
           struct mtx_padalign vmd_free_mtx;
           struct mtx_padalign vmd_pageout_mtx;
           uma_zone_t vmd_pgcache;         /* (c) page free cache. */
           struct vmem *vmd_kernel_arena;  /* (c) per-domain kva R/W arena. */
           struct vmem *vmd_kernel_rwx_arena; /* (c) per-domain kva R/W/X arena. */
           u_int vmd_domain;               /* (c) Domain number. */
           u_int vmd_page_count;           /* (c) Total page count. */
           long vmd_segs;                  /* (c) bitmask of the segments */
           u_int __aligned(CACHE_LINE_SIZE) vmd_free_count; /* (a,f) free page count */
           u_int vmd_pageout_deficit;      /* (a) Estimated number of pages deficit */
           uint8_t vmd_pad[CACHE_LINE_SIZE - (sizeof(u_int) * 2)];
   
           /* Paging control variables, used within single threaded page daemon. */
           struct pidctrl vmd_pid;         /* Pageout controller. */
           boolean_t vmd_oom;
           int vmd_oom_seq;
           int vmd_last_active_scan;
           struct vm_page vmd_markers[PQ_COUNT]; /* (q) markers for queue scans */
           struct vm_page vmd_inacthead; /* marker for LRU-defeating insertions */
           struct vm_page vmd_clock[2]; /* markers for active queue scan */
   
           int vmd_pageout_wanted;         /* (a, p) pageout daemon wait channel */
           int vmd_pageout_pages_needed;   /* (d) page daemon waiting for pages? */
           bool vmd_minset;                /* (d) Are we in vm_min_domains? */
           bool vmd_severeset;             /* (d) Are we in vm_severe_domains? */
           enum {
                   VM_LAUNDRY_IDLE = 0,
                   VM_LAUNDRY_BACKGROUND,
                   VM_LAUNDRY_SHORTFALL
           } vmd_laundry_request;
   
           /* Paging thresholds and targets. */
           u_int vmd_clean_pages_freed;    /* (q) accumulator for laundry thread */
           u_int vmd_background_launder_target; /* (c) */
           u_int vmd_free_reserved;        /* (c) pages reserved for deadlock */
           u_int vmd_free_target;          /* (c) pages desired free */
           u_int vmd_free_min;             /* (c) pages desired free */
           u_int vmd_inactive_target;      /* (c) pages desired inactive */
           u_int vmd_pageout_free_min;     /* (c) min pages reserved for kernel */
           u_int vmd_pageout_wakeup_thresh;/* (c) min pages to wake pagedaemon */
           u_int vmd_interrupt_free_min;   /* (c) reserved pages for int code */
           u_int vmd_free_severe;          /* (c) severe page depletion point */
   
           /* Name for sysctl etc. */
           struct sysctl_oid *vmd_oid;
           char vmd_name[sizeof(__XSTRING(MAXMEMDOM))];
   } __aligned(CACHE_LINE_SIZE);
   
   extern struct vm_domain vm_dom[MAXMEMDOM];
   
   #define VM_DOMAIN(n)            (&vm_dom[(n)])
   #define VM_DOMAIN_EMPTY(n)      (vm_dom[(n)].vmd_page_count == 0)
   
   #define vm_pagequeue_assert_locked(pq)  mtx_assert(&(pq)->pq_mutex, MA_OWNED)
   #define vm_pagequeue_lock(pq)           mtx_lock(&(pq)->pq_mutex)
   #define vm_pagequeue_lockptr(pq)        (&(pq)->pq_mutex)
   #define vm_pagequeue_trylock(pq)        mtx_trylock(&(pq)->pq_mutex)
   #define vm_pagequeue_unlock(pq)         mtx_unlock(&(pq)->pq_mutex)
   
   #define vm_domain_free_assert_locked(n)                                 \
               mtx_assert(vm_domain_free_lockptr((n)), MA_OWNED)
   #define vm_domain_free_assert_unlocked(n)                               \
               mtx_assert(vm_domain_free_lockptr((n)), MA_NOTOWNED)
   #define vm_domain_free_lock(d)                                          \
               mtx_lock(vm_domain_free_lockptr((d)))
   #define vm_domain_free_lockptr(d)                                       \
               (&(d)->vmd_free_mtx)
   #define vm_domain_free_trylock(d)                                       \
               mtx_trylock(vm_domain_free_lockptr((d)))
   #define vm_domain_free_unlock(d)                                        \
               mtx_unlock(vm_domain_free_lockptr((d)))
   
   #define vm_domain_pageout_lockptr(d)                                    \
               (&(d)->vmd_pageout_mtx)
   #define vm_domain_pageout_assert_locked(n)                              \
               mtx_assert(vm_domain_pageout_lockptr((n)), MA_OWNED)
   #define vm_domain_pageout_assert_unlocked(n)                            \
               mtx_assert(vm_domain_pageout_lockptr((n)), MA_NOTOWNED)
   #define vm_domain_pageout_lock(d)                                       \
               mtx_lock(vm_domain_pageout_lockptr((d)))
   #define vm_domain_pageout_unlock(d)                                     \
               mtx_unlock(vm_domain_pageout_lockptr((d)))
   
   static __inline void
   vm_pagequeue_cnt_add(struct vm_pagequeue *pq, int addend)
   {
   
           vm_pagequeue_assert_locked(pq);
           pq->pq_cnt += addend;
   }
   #define vm_pagequeue_cnt_inc(pq)        vm_pagequeue_cnt_add((pq), 1)
   #define vm_pagequeue_cnt_dec(pq)        vm_pagequeue_cnt_add((pq), -1)
   
   static inline void
   vm_batchqueue_init(struct vm_batchqueue *bq)
   {
   
           bq->bq_cnt = 0;
   }
   
   static inline bool
   vm_batchqueue_insert(struct vm_batchqueue *bq, vm_page_t m)
   {
   
           if (bq->bq_cnt < nitems(bq->bq_pa)) {
                   bq->bq_pa[bq->bq_cnt++] = m;
                   return (true);
           }
           return (false);
   }
   
   static inline vm_page_t
   vm_batchqueue_pop(struct vm_batchqueue *bq)
   {
   
           if (bq->bq_cnt == 0)
                   return (NULL);
           return (bq->bq_pa[--bq->bq_cnt]);
   }
   
   void vm_domain_set(struct vm_domain *vmd);
   void vm_domain_clear(struct vm_domain *vmd);
   int vm_domain_allocate(struct vm_domain *vmd, int req, int npages);
   
   /*
    *      vm_pagequeue_domain:
    *
    *      Return the memory domain the page belongs to.
    */
   static inline struct vm_domain *
   vm_pagequeue_domain(vm_page_t m)
   {
   
           return (VM_DOMAIN(vm_phys_domain(m)));
   }
   
   /*
    * Return the number of pages we need to free-up or cache
    * A positive number indicates that we do not have enough free pages.
    */
   static inline int
   vm_paging_target(struct vm_domain *vmd)
   {
   
           return (vmd->vmd_free_target - vmd->vmd_free_count);
   }
   
   /*
    * Returns TRUE if the pagedaemon needs to be woken up.
    */
   static inline int
   vm_paging_needed(struct vm_domain *vmd, u_int free_count)
   {
   
           return (free_count < vmd->vmd_pageout_wakeup_thresh);
   }
   
   /*
    * Returns TRUE if the domain is below the min paging target.
    */
   static inline int
   vm_paging_min(struct vm_domain *vmd)
   {
   
           return (vmd->vmd_free_min > vmd->vmd_free_count);
   }
   
   /*
    * Returns TRUE if the domain is below the severe paging target.
    */
   static inline int
   vm_paging_severe(struct vm_domain *vmd)
   {
   
           return (vmd->vmd_free_severe > vmd->vmd_free_count);
   }
   
   /*
    * Return the number of pages we need to launder.
    * A positive number indicates that we have a shortfall of clean pages.
    */
   static inline int
   vm_laundry_target(struct vm_domain *vmd)
   {
   
           return (vm_paging_target(vmd));
   }
   
   void pagedaemon_wakeup(int domain);
   
   static inline void
   vm_domain_freecnt_inc(struct vm_domain *vmd, int adj)
   {
           u_int old, new;
   
           old = atomic_fetchadd_int(&vmd->vmd_free_count, adj);
           new = old + adj;
           /*
            * Only update bitsets on transitions.  Notice we short-circuit the
            * rest of the checks if we're above min already.
            */
           if (old < vmd->vmd_free_min && (new >= vmd->vmd_free_min ||
               (old < vmd->vmd_free_severe && new >= vmd->vmd_free_severe) ||
               (old < vmd->vmd_pageout_free_min &&
               new >= vmd->vmd_pageout_free_min)))
                   vm_domain_clear(vmd);
   }
   
   #endif  /* _KERNEL */
   #endif                          /* !_VM_PAGEQUEUE_ */

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