/*- * Copyright (c) 2014 Gleb Smirnoff * Copyright (c) 2003, 2005 Alan L. Cox * All rights reserved. * * 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 AUTHOR 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 AUTHOR 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #ifndef NSFBUFS #define NSFBUFS (512 + maxusers * 16) #endif static int nsfbufs; static int nsfbufspeak; static int nsfbufsused; SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0, "Maximum number of sendfile(2) sf_bufs available"); SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0, "Number of sendfile(2) sf_bufs at peak usage"); SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0, "Number of sendfile(2) sf_bufs in use"); static void sf_buf_init(void *arg); SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL); LIST_HEAD(sf_head, sf_buf); /* * A hash table of active sendfile(2) buffers */ static struct sf_head *sf_buf_active; static u_long sf_buf_hashmask; #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) static TAILQ_HEAD(, sf_buf) sf_buf_freelist; static u_int sf_buf_alloc_want; /* * A lock used to synchronize access to the hash table and free list */ static struct mtx sf_buf_lock; /* * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) */ static void sf_buf_init(void *arg) { struct sf_buf *sf_bufs; vm_offset_t sf_base; int i; if (PMAP_HAS_DMAP) return; nsfbufs = NSFBUFS; TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); TAILQ_INIT(&sf_buf_freelist); sf_base = kva_alloc(nsfbufs * PAGE_SIZE); sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, M_WAITOK | M_ZERO); for (i = 0; i < nsfbufs; i++) { sf_bufs[i].kva = sf_base + i * PAGE_SIZE; TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); } sf_buf_alloc_want = 0; mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); } /* * Get an sf_buf from the freelist. May block if none are available. */ struct sf_buf * sf_buf_alloc(struct vm_page *m, int flags) { struct sf_head *hash_list; struct sf_buf *sf; int error; if (PMAP_HAS_DMAP) return ((struct sf_buf *)m); KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0, ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned")); hash_list = &sf_buf_active[SF_BUF_HASH(m)]; mtx_lock(&sf_buf_lock); LIST_FOREACH(sf, hash_list, list_entry) { if (sf->m == m) { sf->ref_count++; if (sf->ref_count == 1) { TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); nsfbufsused++; nsfbufspeak = imax(nsfbufspeak, nsfbufsused); } #if defined(SMP) && defined(SFBUF_CPUSET) sf_buf_shootdown(sf, flags); #endif goto done; } } while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { if (flags & SFB_NOWAIT) goto done; sf_buf_alloc_want++; SFSTAT_INC(sf_allocwait); error = msleep(&sf_buf_freelist, &sf_buf_lock, (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); sf_buf_alloc_want--; /* * If we got a signal, don't risk going back to sleep. */ if (error) goto done; } TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); if (sf->m != NULL) LIST_REMOVE(sf, list_entry); LIST_INSERT_HEAD(hash_list, sf, list_entry); sf->ref_count = 1; sf->m = m; nsfbufsused++; nsfbufspeak = imax(nsfbufspeak, nsfbufsused); sf_buf_map(sf, flags); done: mtx_unlock(&sf_buf_lock); return (sf); } /* * Remove a reference from the given sf_buf, adding it to the free * list when its reference count reaches zero. A freed sf_buf still, * however, retains its virtual-to-physical mapping until it is * recycled or reactivated by sf_buf_alloc(9). */ void sf_buf_free(struct sf_buf *sf) { if (PMAP_HAS_DMAP) return; mtx_lock(&sf_buf_lock); sf->ref_count--; if (sf->ref_count == 0) { TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); nsfbufsused--; if (sf_buf_unmap(sf)) { sf->m = NULL; LIST_REMOVE(sf, list_entry); } if (sf_buf_alloc_want > 0) wakeup(&sf_buf_freelist); } mtx_unlock(&sf_buf_lock); } void sf_buf_ref(struct sf_buf *sf) { if (PMAP_HAS_DMAP) return; mtx_lock(&sf_buf_lock); KASSERT(sf->ref_count > 0, ("%s: sf %p not allocated", __func__, sf)); sf->ref_count++; mtx_unlock(&sf_buf_lock); } #ifdef SFBUF_PROCESS_PAGE /* * Run callback function on sf_buf that holds a certain page. */ boolean_t sf_buf_process_page(vm_page_t m, void (*cb)(struct sf_buf *)) { struct sf_head *hash_list; struct sf_buf *sf; hash_list = &sf_buf_active[SF_BUF_HASH(m)]; mtx_lock(&sf_buf_lock); LIST_FOREACH(sf, hash_list, list_entry) { if (sf->m == m) { cb(sf); mtx_unlock(&sf_buf_lock); return (TRUE); } } mtx_unlock(&sf_buf_lock); return (FALSE); } #endif /* SFBUF_PROCESS_PAGE */