From 0c59f7ff0112abd1261afb8f21b7c00fc5e37885 Mon Sep 17 00:00:00 2001 From: Maria Matejka Date: Wed, 9 Mar 2022 09:13:31 +0100 Subject: [PATCH] Revert "Bound allocated pages to resource pools with page caches to avoid unnecessary syscalls" This reverts commit 7f0e59820899c30a243c18556ce2e3fb72d6d221. --- lib/resource.c | 58 --------------------------------------------- lib/resource.h | 8 +++---- lib/slab.c | 24 +++++++++---------- sysdep/unix/alloc.c | 37 ++++++++++++++++------------- 4 files changed, 35 insertions(+), 92 deletions(-) diff --git a/lib/resource.c b/lib/resource.c index 0ad886d9..4c4b92ec 100644 --- a/lib/resource.c +++ b/lib/resource.c @@ -31,18 +31,9 @@ struct pool { resource r; list inside; - struct pool_pages *pages; const char *name; }; -struct pool_pages { - uint free; - uint used; - void *ptr[0]; -}; - -#define POOL_PAGES_MAX ((page_size - sizeof(struct pool_pages)) / sizeof (void *)) - static void pool_dump(resource *); static void pool_free(resource *); static resource *pool_lookup(resource *, unsigned long); @@ -59,10 +50,6 @@ static struct resclass pool_class = { pool root_pool; -void *alloc_sys_page(void); -void free_sys_page(void *); -void resource_sys_init(void); - static int indent; /** @@ -95,14 +82,6 @@ pool_free(resource *P) xfree(r); r = rr; } - - if (p->pages) - { - ASSERT_DIE(!p->pages->used); - for (uint i=0; ipages->free; i++) - free_sys_page(p->pages->ptr[i]); - free_sys_page(p->pages); - } } static void @@ -128,9 +107,6 @@ pool_memsize(resource *P) WALK_LIST(r, p->inside) sum += rmemsize(r); - if (p->pages) - sum += page_size * (p->pages->used + p->pages->free + 1); - return sum; } @@ -283,7 +259,6 @@ rlookup(unsigned long a) void resource_init(void) { - resource_sys_init(); root_pool.r.class = &pool_class; root_pool.name = "Root"; init_list(&root_pool.inside); @@ -450,39 +425,6 @@ mb_free(void *m) rfree(b); } -void * -alloc_page(pool *p) -{ - if (!p->pages) - { - p->pages = alloc_sys_page(); - p->pages->free = 0; - p->pages->used = 1; - } - else - p->pages->used++; - - if (p->pages->free) - { - void *ptr = p->pages->ptr[--p->pages->free]; - bzero(ptr, page_size); - return ptr; - } - else - return alloc_sys_page(); -} - -void -free_page(pool *p, void *ptr) -{ - ASSERT_DIE(p->pages); - p->pages->used--; - - if (p->pages->free >= POOL_PAGES_MAX) - return free_sys_page(ptr); - else - p->pages->ptr[p->pages->free++] = ptr; -} #define STEP_UP(x) ((x) + (x)/2 + 4) diff --git a/lib/resource.h b/lib/resource.h index 26030aea..1b9fed33 100644 --- a/lib/resource.h +++ b/lib/resource.h @@ -94,12 +94,10 @@ void sl_free(slab *, void *); void buffer_realloc(void **buf, unsigned *size, unsigned need, unsigned item_size); -extern long page_size; - /* Allocator of whole pages; for use in slabs and other high-level allocators. */ -void *alloc_page(pool *); -void free_page(pool *, void *); -#define PAGE_HEAD(x) ((void *) (((intptr_t) (x)) & ~(page_size-1))) +u64 get_page_size(void); +void *alloc_page(void); +void free_page(void *); #ifdef HAVE_LIBDMALLOC /* diff --git a/lib/slab.c b/lib/slab.c index 70aa776a..8d16c433 100644 --- a/lib/slab.c +++ b/lib/slab.c @@ -152,7 +152,6 @@ slab_memsize(resource *r) struct slab { resource r; - pool *p; uint obj_size, head_size, head_bitfield_len; uint objs_per_slab, num_empty_heads, data_size; list empty_heads, partial_heads, full_heads; @@ -192,7 +191,6 @@ slab * sl_new(pool *p, uint size) { slab *s = ralloc(p, &sl_class); - s->p = p; uint align = sizeof(struct sl_alignment); if (align < sizeof(int)) align = sizeof(int); @@ -201,6 +199,7 @@ sl_new(pool *p, uint size) s->obj_size = size; s->head_size = sizeof(struct sl_head); + u64 page_size = get_page_size(); do { s->objs_per_slab = (page_size - s->head_size) / size; @@ -269,9 +268,9 @@ no_partial: s->num_empty_heads--; goto okay; } - h = alloc_page(s->p); + h = alloc_page(); #ifdef POISON - memset(h, 0xba, page_size); + memset(h, 0xba, get_page_size()); #endif ASSERT_DIE(SL_GET_HEAD(h) == h); memset(h, 0, s->head_size); @@ -330,9 +329,9 @@ sl_free(slab *s, void *oo) if (s->num_empty_heads >= MAX_EMPTY_HEADS) { #ifdef POISON - memset(h, 0xde, page_size); + memset(h, 0xde, get_page_size()); #endif - free_page(s->p, h); + free_page(h); } else { @@ -349,11 +348,11 @@ slab_free(resource *r) struct sl_head *h, *g; WALK_LIST_DELSAFE(h, g, s->empty_heads) - free_page(s->p, h); + free_page(h); WALK_LIST_DELSAFE(h, g, s->partial_heads) - free_page(s->p, h); + free_page(h); WALK_LIST_DELSAFE(h, g, s->full_heads) - free_page(s->p, h); + free_page(h); } static void @@ -386,8 +385,7 @@ slab_memsize(resource *r) WALK_LIST(h, s->full_heads) heads++; -// return ALLOC_OVERHEAD + sizeof(struct slab) + heads * (ALLOC_OVERHEAD + page_size); - return ALLOC_OVERHEAD + sizeof(struct slab); /* The page sizes are accounted for in the pool */ + return ALLOC_OVERHEAD + sizeof(struct slab) + heads * (ALLOC_OVERHEAD + get_page_size()); } static resource * @@ -397,10 +395,10 @@ slab_lookup(resource *r, unsigned long a) struct sl_head *h; WALK_LIST(h, s->partial_heads) - if ((unsigned long) h < a && (unsigned long) h + page_size < a) + if ((unsigned long) h < a && (unsigned long) h + get_page_size() < a) return r; WALK_LIST(h, s->full_heads) - if ((unsigned long) h < a && (unsigned long) h + page_size < a) + if ((unsigned long) h < a && (unsigned long) h + get_page_size() < a) return r; return NULL; } diff --git a/sysdep/unix/alloc.c b/sysdep/unix/alloc.c index f6296afe..c525f713 100644 --- a/sysdep/unix/alloc.c +++ b/sysdep/unix/alloc.c @@ -16,36 +16,41 @@ #include #endif -long page_size = 0; - #ifdef HAVE_MMAP +static u64 page_size = 0; static _Bool use_fake = 0; #else -static _Bool use_fake = 1; +static const u64 page_size = 4096; /* Fake page size */ #endif -void resource_sys_init(void) +u64 get_page_size(void) { -#ifdef HAVE_MMAP - if (!(page_size = sysconf(_SC_PAGESIZE))) - die("System page size must be non-zero"); + if (page_size) + return page_size; - if ((u64_popcount(page_size) > 1) || (page_size > 16384)) +#ifdef HAVE_MMAP + if (page_size = sysconf(_SC_PAGESIZE)) { -#endif - /* Too big or strange page, use the aligned allocator instead */ - page_size = 4096; - use_fake = 1; + if ((u64_popcount(page_size) > 1) || (page_size > 16384)) + { + /* Too big or strange page, use the aligned allocator instead */ + page_size = 4096; + use_fake = 1; + } + return page_size; } + + bug("Page size must be non-zero"); +#endif } void * -alloc_sys_page(void) +alloc_page(void) { #ifdef HAVE_MMAP if (!use_fake) { - void *ret = mmap(NULL, page_size, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + void *ret = mmap(NULL, get_page_size(), PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (ret == MAP_FAILED) bug("mmap(%lu) failed: %m", page_size); return ret; @@ -61,12 +66,12 @@ alloc_sys_page(void) } void -free_sys_page(void *ptr) +free_page(void *ptr) { #ifdef HAVE_MMAP if (!use_fake) { - if (munmap(ptr, page_size) < 0) + if (munmap(ptr, get_page_size()) < 0) bug("munmap(%p) failed: %m", ptr); } else