Bound allocated pages to resource pools with page caches to avoid unnecessary syscalls (7f0e5982) · Commits · 戴 / Bird

lib/resource.c

+58 −0

Original line number	Diff line number	Diff line
		@@ -31,9 +31,18 @@
		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);
		@@ -50,6 +59,10 @@ 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;

		/**
		@@ -82,6 +95,14 @@ pool_free(resource *P)
		xfree(r);
		r = rr;
		}

		if (p->pages)
		{
		ASSERT_DIE(!p->pages->used);
		for (uint i=0; i<p->pages->free; i++)
		free_sys_page(p->pages->ptr[i]);
		free_sys_page(p->pages);
		}
		}

		static void
		@@ -107,6 +128,9 @@ 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;
		}

		@@ -259,6 +283,7 @@ 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);
		@@ -425,6 +450,39 @@ 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)

lib/resource.h

+5 −3

Original line number	Diff line number	Diff line
		@@ -94,10 +94,12 @@ 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. */
		u64 get_page_size(void);
		void *alloc_page(void);
		void free_page(void *);
		void alloc_page(pool );
		void free_page(pool , void );
		#define PAGE_HEAD(x) ((void *) (((intptr_t) (x)) & ~(page_size-1)))

		#ifdef HAVE_LIBDMALLOC
		/*

lib/slab.c

+13 −11

Original line number	Diff line number	Diff line
		@@ -152,6 +152,7 @@ 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;
		@@ -191,6 +192,7 @@ 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);
		@@ -199,7 +201,6 @@ 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;
		@@ -268,9 +269,9 @@ no_partial:
		s->num_empty_heads--;
		goto okay;
		}
		h = alloc_page();
		h = alloc_page(s->p);
		#ifdef POISON
		memset(h, 0xba, get_page_size());
		memset(h, 0xba, page_size);
		#endif
		ASSERT_DIE(SL_GET_HEAD(h) == h);
		memset(h, 0, s->head_size);
		@@ -329,9 +330,9 @@ sl_free(slab s, void oo)
		if (s->num_empty_heads >= MAX_EMPTY_HEADS)
		{
		#ifdef POISON
		memset(h, 0xde, get_page_size());
		memset(h, 0xde, page_size);
		#endif
		free_page(h);
		free_page(s->p, h);
		}
		else
		{
		@@ -348,11 +349,11 @@ slab_free(resource *r)
		struct sl_head h, g;

		WALK_LIST_DELSAFE(h, g, s->empty_heads)
		free_page(h);
		free_page(s->p, h);
		WALK_LIST_DELSAFE(h, g, s->partial_heads)
		free_page(h);
		free_page(s->p, h);
		WALK_LIST_DELSAFE(h, g, s->full_heads)
		free_page(h);
		free_page(s->p, h);
		}

		static void
		@@ -385,7 +386,8 @@ slab_memsize(resource *r)
		WALK_LIST(h, s->full_heads)
		heads++;

		return ALLOC_OVERHEAD + sizeof(struct slab) + heads * (ALLOC_OVERHEAD + get_page_size());
		// 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 */
		}

		static resource *
		@@ -395,10 +397,10 @@ 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 + get_page_size() < a)
		if ((unsigned long) h < a && (unsigned long) h + page_size < a)
		return r;
		WALK_LIST(h, s->full_heads)
		if ((unsigned long) h < a && (unsigned long) h + get_page_size() < a)
		if ((unsigned long) h < a && (unsigned long) h + page_size < a)
		return r;
		return NULL;
		}

sysdep/unix/alloc.c

+16 −21

Original line number	Diff line number	Diff line
		@@ -16,41 +16,36 @@
		#include <sys/mman.h>
		#endif

		long page_size = 0;

		#ifdef HAVE_MMAP
		static u64 page_size = 0;
		static _Bool use_fake = 0;
		#else
		static const u64 page_size = 4096; /* Fake page size */
		static _Bool use_fake = 1;
		#endif

		u64 get_page_size(void)
		void resource_sys_init(void)
		{
		if (page_size)
		return page_size;

		#ifdef HAVE_MMAP
		if (page_size = sysconf(_SC_PAGESIZE))
		{
		if (!(page_size = sysconf(_SC_PAGESIZE)))
		die("System page size must be non-zero");

		if ((u64_popcount(page_size) > 1) \|\| (page_size > 16384))
		{
		#endif
		/* 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_page(void)
		alloc_sys_page(void)
		{
		#ifdef HAVE_MMAP
		if (!use_fake)
		{
		void *ret = mmap(NULL, get_page_size(), PROT_WRITE \| PROT_READ, MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
		void *ret = mmap(NULL, 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;
		@@ -66,12 +61,12 @@ alloc_page(void)
		}

		void
		free_page(void *ptr)
		free_sys_page(void *ptr)
		{
		#ifdef HAVE_MMAP
		if (!use_fake)
		{
		if (munmap(ptr, get_page_size()) < 0)
		if (munmap(ptr, page_size) < 0)
		bug("munmap(%p) failed: %m", ptr);
		}
		else

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