diff options
author | Otto Moerbeek <otto@cvs.openbsd.org> | 2018-01-08 12:20:24 +0000 |
---|---|---|
committer | Otto Moerbeek <otto@cvs.openbsd.org> | 2018-01-08 12:20:24 +0000 |
commit | 470f344f0c8f07e39cd9168f6fa91f24c213f0f2 (patch) | |
tree | 492212765447f15537cee0e3d9722712bc6091d3 | |
parent | f2cce1878dc70d02fdee94511c723d32ff377cb6 (diff) |
optimization and some cleanup; mostly from kshe (except the unmap() part)
-rw-r--r-- | lib/libc/stdlib/malloc.c | 118 |
1 files changed, 51 insertions, 67 deletions
diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c index 02349d9ef9b..b0083cb91e8 100644 --- a/lib/libc/stdlib/malloc.c +++ b/lib/libc/stdlib/malloc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: malloc.c,v 1.238 2018/01/01 12:41:48 otto Exp $ */ +/* $OpenBSD: malloc.c,v 1.239 2018/01/08 12:20:23 otto Exp $ */ /* * Copyright (c) 2008, 2010, 2011, 2016 Otto Moerbeek <otto@drijf.net> * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org> @@ -376,12 +376,11 @@ omalloc_parseopt(char opt) case 'X': mopts.malloc_xmalloc = 1; break; - default: { + default: dprintf(STDERR_FILENO, "malloc() warning: " "unknown char in MALLOC_OPTIONS\n"); break; } - } } static void @@ -448,9 +447,6 @@ omalloc_init(void) ; } -/* - * Initialize a dir_info, which should have been cleared by caller - */ static void omalloc_poolinit(struct dir_info **dp) { @@ -502,7 +498,7 @@ omalloc_grow(struct dir_info *d) size_t i; struct region_info *p; - if (d->regions_total > SIZE_MAX / sizeof(struct region_info) / 2 ) + if (d->regions_total > SIZE_MAX / sizeof(struct region_info) / 2) return 1; newtotal = d->regions_total * 2; @@ -641,9 +637,9 @@ static void unmap(struct dir_info *d, void *p, size_t sz, int clear) { size_t psz = sz >> MALLOC_PAGESHIFT; - size_t rsz, tounmap; + size_t rsz; struct region_info *r; - u_int i, offset; + u_int i, offset, mask; if (sz != PAGEROUND(sz)) wrterror(d, "munmap round"); @@ -662,30 +658,34 @@ unmap(struct dir_info *d, void *p, size_t sz, int clear) STATS_SUB(d->malloc_used, sz); return; } - tounmap = 0; - if (psz > rsz) - tounmap = psz - rsz; offset = getrbyte(d); - for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) { - r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)]; - if (r->p != NULL) { - rsz = r->size << MALLOC_PAGESHIFT; - if (munmap(r->p, rsz)) - wrterror(d, "munmap %p", r->p); - r->p = NULL; - if (tounmap > r->size) - tounmap -= r->size; - else - tounmap = 0; - d->free_regions_size -= r->size; - r->size = 0; - STATS_SUB(d->malloc_used, rsz); + mask = mopts.malloc_cache - 1; + if (psz > rsz) { + size_t tounmap = psz - rsz; + i = 0; + for (;;) { + r = &d->free_regions[(i + offset) & mask]; + if (r->p != NULL) { + rsz = r->size << MALLOC_PAGESHIFT; + if (munmap(r->p, rsz)) + wrterror(d, "munmap %p", r->p); + r->p = NULL; + if (tounmap > r->size) + tounmap -= r->size; + else + tounmap = 0; + d->free_regions_size -= r->size; + STATS_SUB(d->malloc_used, rsz); + if (tounmap == 0) { + offset = i; + break; + } + } + i++; } } - if (tounmap > 0) - wrterror(d, "malloc cache underflow"); - for (i = 0; i < mopts.malloc_cache; i++) { - r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)]; + for (i = 0; ; i++) { + r = &d->free_regions[(i + offset) & mask]; if (r->p == NULL) { if (clear) memset(p, 0, sz - mopts.malloc_guard); @@ -702,8 +702,6 @@ unmap(struct dir_info *d, void *p, size_t sz, int clear) break; } } - if (i == mopts.malloc_cache) - wrterror(d, "malloc free slot lost"); if (d->free_regions_size > mopts.malloc_cache) wrterror(d, "malloc cache overflow"); } @@ -723,7 +721,6 @@ zapcacheregion(struct dir_info *d, void *p, size_t len) wrterror(d, "munmap %p", r->p); r->p = NULL; d->free_regions_size -= r->size; - r->size = 0; STATS_SUB(d->malloc_used, rsz); } } @@ -760,7 +757,6 @@ map(struct dir_info *d, void *hint, size_t sz, int zero_fill) if (r->size == psz) { p = r->p; r->p = NULL; - r->size = 0; d->free_regions_size -= psz; if (mopts.malloc_freeunmap) mprotect(p, sz, PROT_READ | PROT_WRITE); @@ -808,10 +804,7 @@ init_chunk_info(struct dir_info *d, struct chunk_info *p, int bits) int i; if (bits == 0) { - p->shift = 1; - i = MALLOC_MINSIZE - 1; - while (i >>= 1) - p->shift++; + p->shift = MALLOC_MINSHIFT; p->total = p->free = MALLOC_PAGESIZE >> p->shift; p->size = 0; p->offset = 0xdead; @@ -824,13 +817,9 @@ init_chunk_info(struct dir_info *d, struct chunk_info *p, int bits) p->canary = (u_short)d->canary1; /* set all valid bits in the bitmap */ - for (i = 0; p->total - i >= MALLOC_BITS; i += MALLOC_BITS) - p->bits[i / MALLOC_BITS] = (u_short)~0U; - - if (i < p->total) - p->bits[i / MALLOC_BITS] = 0; - for (; i < p->total; i++) - p->bits[i / MALLOC_BITS] |= (u_short)1U << (i % MALLOC_BITS); + i = p->total - 1; + memset(p->bits, 0xff, sizeof(p->bits[0]) * (i / MALLOC_BITS)); + p->bits[i / MALLOC_BITS] = (2U << (i % MALLOC_BITS)) - 1; } static struct chunk_info * @@ -907,23 +896,20 @@ err: static int find_chunksize(size_t size) { - int i, j; + int r; - /* Don't bother with anything less than this */ - /* unless we have a malloc(0) requests */ - if (size != 0 && size < MALLOC_MINSIZE) + /* malloc(0) is special */ + if (size == 0) + return 0; + + if (size < MALLOC_MINSIZE) size = MALLOC_MINSIZE; + size--; - /* Find the right bucket */ - if (size == 0) - j = 0; - else { - j = MALLOC_MINSHIFT; - i = (size - 1) >> (MALLOC_MINSHIFT - 1); - while (i >>= 1) - j++; - } - return j; + r = MALLOC_MINSHIFT; + while (size >> r) + r++; + return r; } static void @@ -1013,7 +999,7 @@ found: *lp ^= u; /* If there are no more free, remove from free-list */ - if (!--bp->free) + if (--bp->free == 0) LIST_REMOVE(bp, entries); /* Adjust to the real offset of that chunk */ @@ -1048,8 +1034,8 @@ validate_canary(struct dir_info *d, u_char *ptr, size_t sz, size_t allocated) while (p < q) { if (*p != SOME_JUNK) { wrterror(d, "chunk canary corrupted %p %#tx@%#zx%s", - ptr, p - ptr, sz, *p == SOME_FREEJUNK ? - " (double free?)" : ""); + ptr, p - ptr, sz, + *p == SOME_FREEJUNK ? " (double free?)" : ""); } p++; } @@ -1173,8 +1159,7 @@ omalloc(struct dir_info *pool, size_t sz, int zero_fill, void *f) else memset(p, SOME_JUNK, psz - mopts.malloc_guard); - } - else if (mopts.chunk_canaries) + } else if (mopts.chunk_canaries) fill_canary(p, sz - mopts.malloc_guard, psz - mopts.malloc_guard); } @@ -1225,7 +1210,7 @@ _malloc_init(int from_rthreads) max = from_rthreads ? _MALLOC_MUTEXES : 1; if (((uintptr_t)&malloc_readonly & MALLOC_PAGEMASK) == 0) mprotect(&malloc_readonly, sizeof(malloc_readonly), - PROT_READ | PROT_WRITE); + PROT_READ | PROT_WRITE); for (i = 0; i < max; i++) { if (mopts.malloc_pool[i]) continue; @@ -2030,8 +2015,7 @@ omemalign(struct dir_info *pool, size_t alignment, size_t sz, int zero_fill, SOME_JUNK, psz - sz); else memset(p, SOME_JUNK, psz - mopts.malloc_guard); - } - else if (mopts.chunk_canaries) + } else if (mopts.chunk_canaries) fill_canary(p, sz - mopts.malloc_guard, psz - mopts.malloc_guard); |