diff options
Diffstat (limited to 'zfs/lib/libumem/vmem_sbrk.c')
-rw-r--r-- | zfs/lib/libumem/vmem_sbrk.c | 268 |
1 files changed, 0 insertions, 268 deletions
diff --git a/zfs/lib/libumem/vmem_sbrk.c b/zfs/lib/libumem/vmem_sbrk.c deleted file mode 100644 index 20bfb7345..000000000 --- a/zfs/lib/libumem/vmem_sbrk.c +++ /dev/null @@ -1,268 +0,0 @@ -/* - * CDDL HEADER START - * - * The contents of this file are subject to the terms of the - * Common Development and Distribution License (the "License"). - * You may not use this file except in compliance with the License. - * - * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE - * or http://www.opensolaris.org/os/licensing. - * See the License for the specific language governing permissions - * and limitations under the License. - * - * When distributing Covered Code, include this CDDL HEADER in each - * file and include the License file at usr/src/OPENSOLARIS.LICENSE. - * If applicable, add the following below this CDDL HEADER, with the - * fields enclosed by brackets "[]" replaced with your own identifying - * information: Portions Copyright [yyyy] [name of copyright owner] - * - * CDDL HEADER END - */ - -/* - * Copyright 2008 Sun Microsystems, Inc. All rights reserved. - * Use is subject to license terms. - */ - -#pragma ident "%Z%%M% %I% %E% SMI" - -/* - * The structure of the sbrk backend: - * - * +-----------+ - * | sbrk_top | - * +-----------+ - * | (vmem_sbrk_alloc(), vmem_free()) - * | - * +-----------+ - * | sbrk_heap | - * +-----------+ - * | | ... | (vmem_alloc(), vmem_free()) - * <other arenas> - * - * The sbrk_top arena holds all controlled memory. vmem_sbrk_alloc() handles - * allocations from it, including growing the heap when we run low. - * - * Growing the heap is complicated by the fact that we have to extend the - * sbrk_top arena (using _vmem_extend_alloc()), and that can fail. Since - * other threads may be actively allocating, we can't return the memory. - * - * Instead, we put it on a doubly-linked list, sbrk_fails, which we search - * before calling sbrk(). - */ - -#include <errno.h> -#include <limits.h> -#include <sys/sysmacros.h> -#include <sys/mman.h> -#include <unistd.h> - -#include "vmem_base.h" - -#include "misc.h" - -size_t vmem_sbrk_pagesize = 0; /* the preferred page size of the heap */ - -#define VMEM_SBRK_MINALLOC (64 * 1024) -size_t vmem_sbrk_minalloc = VMEM_SBRK_MINALLOC; /* minimum allocation */ - -static size_t real_pagesize; -static vmem_t *sbrk_heap; - -typedef struct sbrk_fail { - struct sbrk_fail *sf_next; - struct sbrk_fail *sf_prev; - void *sf_base; /* == the sbrk_fail's address */ - size_t sf_size; /* the size of this buffer */ -} sbrk_fail_t; - -static sbrk_fail_t sbrk_fails = { - &sbrk_fails, - &sbrk_fails, - NULL, - 0 -}; - -static mutex_t sbrk_faillock = DEFAULTMUTEX; - -/* - * Try to extend src with [pos, pos + size). - * - * If it fails, add the block to the sbrk_fails list. - */ -static void * -vmem_sbrk_extend_alloc(vmem_t *src, void *pos, size_t size, size_t alloc, - int vmflags) -{ - sbrk_fail_t *fnext, *fprev, *fp; - void *ret; - - ret = _vmem_extend_alloc(src, pos, size, alloc, vmflags); - if (ret != NULL) - return (ret); - - fp = (sbrk_fail_t *)pos; - - ASSERT(sizeof (sbrk_fail_t) <= size); - - fp->sf_base = pos; - fp->sf_size = size; - - (void) mutex_lock(&sbrk_faillock); - fp->sf_next = fnext = &sbrk_fails; - fp->sf_prev = fprev = sbrk_fails.sf_prev; - fnext->sf_prev = fp; - fprev->sf_next = fp; - (void) mutex_unlock(&sbrk_faillock); - - return (NULL); -} - -/* - * Try to add at least size bytes to src, using the sbrk_fails list - */ -static void * -vmem_sbrk_tryfail(vmem_t *src, size_t size, int vmflags) -{ - sbrk_fail_t *fp; - - (void) mutex_lock(&sbrk_faillock); - for (fp = sbrk_fails.sf_next; fp != &sbrk_fails; fp = fp->sf_next) { - if (fp->sf_size >= size) { - fp->sf_next->sf_prev = fp->sf_prev; - fp->sf_prev->sf_next = fp->sf_next; - fp->sf_next = fp->sf_prev = NULL; - break; - } - } - (void) mutex_unlock(&sbrk_faillock); - - if (fp != &sbrk_fails) { - ASSERT(fp->sf_base == (void *)fp); - return (vmem_sbrk_extend_alloc(src, fp, fp->sf_size, size, - vmflags)); - } - /* - * nothing of the right size on the freelist - */ - return (NULL); -} - -static void * -vmem_sbrk_alloc(vmem_t *src, size_t size, int vmflags) -{ - extern void *_sbrk_grow_aligned(size_t min_size, size_t low_align, - size_t high_align, size_t *actual_size); - - void *ret; - void *buf; - size_t buf_size; - - int old_errno = errno; - - ret = vmem_alloc(src, size, VM_NOSLEEP); - if (ret != NULL) { - errno = old_errno; - return (ret); - } - - /* - * The allocation failed. We need to grow the heap. - * - * First, try to use any buffers which failed earlier. - */ - if (sbrk_fails.sf_next != &sbrk_fails && - (ret = vmem_sbrk_tryfail(src, size, vmflags)) != NULL) - return (ret); - - buf_size = MAX(size, vmem_sbrk_minalloc); - - /* - * buf_size gets overwritten with the actual allocated size - */ - buf = _sbrk_grow_aligned(buf_size, real_pagesize, vmem_sbrk_pagesize, - &buf_size); - - if (buf != MAP_FAILED) { - ret = vmem_sbrk_extend_alloc(src, buf, buf_size, size, vmflags); - if (ret != NULL) { - errno = old_errno; - return (ret); - } - } - - /* - * Growing the heap failed. The vmem_alloc() above called umem_reap(). - */ - ASSERT((vmflags & VM_NOSLEEP) == VM_NOSLEEP); - - errno = old_errno; - return (NULL); -} - -/* - * fork1() support - */ -void -vmem_sbrk_lockup(void) -{ - (void) mutex_lock(&sbrk_faillock); -} - -void -vmem_sbrk_release(void) -{ - (void) mutex_unlock(&sbrk_faillock); -} - -vmem_t * -vmem_sbrk_arena(vmem_alloc_t **a_out, vmem_free_t **f_out) -{ - if (sbrk_heap == NULL) { - size_t heap_size; - - real_pagesize = sysconf(_SC_PAGESIZE); - - heap_size = vmem_sbrk_pagesize; - - if (issetugid()) { - heap_size = 0; - } else if (heap_size != 0 && !ISP2(heap_size)) { - heap_size = 0; - log_message("ignoring bad pagesize: 0x%p\n", heap_size); - } - if (heap_size <= real_pagesize) { - heap_size = real_pagesize; - } else { - struct memcntl_mha mha; - mha.mha_cmd = MHA_MAPSIZE_BSSBRK; - mha.mha_flags = 0; - mha.mha_pagesize = heap_size; - - if (memcntl(NULL, 0, MC_HAT_ADVISE, (char *)&mha, 0, 0) - == -1) { - log_message("unable to set MAPSIZE_BSSBRK to " - "0x%p\n", heap_size); - heap_size = real_pagesize; - } - } - vmem_sbrk_pagesize = heap_size; - - /* validate vmem_sbrk_minalloc */ - if (vmem_sbrk_minalloc < VMEM_SBRK_MINALLOC) - vmem_sbrk_minalloc = VMEM_SBRK_MINALLOC; - vmem_sbrk_minalloc = P2ROUNDUP(vmem_sbrk_minalloc, heap_size); - - sbrk_heap = vmem_init("sbrk_top", real_pagesize, - vmem_sbrk_alloc, vmem_free, - "sbrk_heap", NULL, 0, real_pagesize, - vmem_alloc, vmem_free); - } - - if (a_out != NULL) - *a_out = vmem_alloc; - if (f_out != NULL) - *f_out = vmem_free; - - return (sbrk_heap); -} |