Directly mapped pages are kept for future use if temporarily not needed (644e9ca9) · Commits · 戴 / Bird

lib/resource.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -98,6 +98,7 @@ void buffer_realloc(void *buf, unsigned size, unsigned need, unsigned item_siz
		u64 get_page_size(void);
		void *alloc_page(void);
		void free_page(void *);
		extern uint pages_kept;

		#ifdef HAVE_LIBDMALLOC
		/*

nest/cmds.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -91,7 +91,12 @@ cmd_show_memory(void)
		print_size("Routing tables:", rmemsize(rt_table_pool));
		print_size("Route attributes:", rmemsize(rta_pool));
		print_size("Protocols:", rmemsize(proto_pool));
		print_size("Total:", rmemsize(&root_pool));
		size_t total = rmemsize(&root_pool);
		#ifdef HAVE_MMAP
		print_size("Standby memory:", get_page_size() * pages_kept);
		total += get_page_size() * pages_kept;
		#endif
		print_size("Total:", total);
		cli_msg(0, "");
		}

sysdep/unix/alloc.c

+51 −2

Original line number	Diff line number	Diff line
		@@ -8,6 +8,8 @@

		#include "nest/bird.h"
		#include "lib/resource.h"
		#include "lib/lists.h"
		#include "lib/event.h"

		#include <stdlib.h>
		#include <unistd.h>
		@@ -17,8 +19,17 @@
		#endif

		#ifdef HAVE_MMAP
		#define KEEP_PAGES 512

		static u64 page_size = 0;
		static _Bool use_fake = 0;

		uint pages_kept = 0;
		static list pages_list;

		static void cleanup_pages(void *data);
		static event page_cleanup_event = { .hook = cleanup_pages };

		#else
		static const u64 page_size = 4096; /* Fake page size */
		#endif
		@@ -48,6 +59,15 @@ void *
		alloc_page(void)
		{
		#ifdef HAVE_MMAP
		if (pages_kept)
		{
		node *page = TAIL(pages_list);
		rem_node(page);
		pages_kept--;
		memset(page, 0, get_page_size());
		return page;
		}

		if (!use_fake)
		{
		void *ret = mmap(NULL, get_page_size(), PROT_WRITE \| PROT_READ, MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
		@@ -71,10 +91,39 @@ free_page(void *ptr)
		#ifdef HAVE_MMAP
		if (!use_fake)
		{
		if (munmap(ptr, get_page_size()) < 0)
		bug("munmap(%p) failed: %m", ptr);
		if (!pages_kept)
		init_list(&pages_list);

		memset(ptr, 0, sizeof(node));
		add_tail(&pages_list, ptr);

		if (++pages_kept > KEEP_PAGES)
		ev_schedule(&page_cleanup_event);
		}
		else
		#endif
		free(ptr);
		}

		#ifdef HAVE_MMAP
		static void
		cleanup_pages(void *data UNUSED)
		{
		for (uint seen = 0; (pages_kept > KEEP_PAGES) && (seen < KEEP_PAGES); seen++)
		{
		void *ptr = HEAD(pages_list);
		rem_node(ptr);
		if (munmap(ptr, get_page_size()) == 0)
		pages_kept--;
		#ifdef ENOMEM
		else if (errno == ENOMEM)
		add_tail(&pages_list, ptr);
		#endif
		else
		bug("munmap(%p) failed: %m", ptr);
		}

		if (pages_kept > KEEP_PAGES)
		ev_schedule(&page_cleanup_event);
		}
		#endif

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