1. Prior to r214782, UMA did not support multipage allocations before

uma_startup2() was called.  Thus, setting the variable "booted" to true in
uma_startup() was ok on machines with UMA_MD_SMALL_ALLOC defined, because
any allocations made after uma_startup() but before uma_startup2() could be
satisfied by uma_small_alloc().  Now, however, some multipage allocations
are necessary before uma_startup2() just to allocate zone structures on
machines with a large number of processors.  Thus, a Boolean can no longer
effectively describe the state of the UMA allocator.  Instead, make "booted"
have three values to describe how far initialization has progressed.  This
allows multipage allocations to continue using startup_alloc() until
uma_startup2(), but single-page allocations may begin using
uma_small_alloc() after uma_startup().

2. With the aforementioned change, only a modest increase in boot pages is
necessary to boot UMA on a large number of processors.

3. Retire UMA_MD_SMALL_ALLOC_NEEDS_VM.  It has only been used between
r182028 and r204128.

Reviewed by:	attilio [1], nwhitehorn [3]
Tested by:	sbruno

2 files changed, 9 insertions, 8 deletions

diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index 7fb120a..f969547 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -134,6 +134,8 @@ static struct mtx uma_boot_pages_mtx;
 
 /* Is the VM done starting up? */
 static int booted = 0;
+#define	UMA_STARTUP	1
+#define	UMA_STARTUP2	2
 
 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
 static u_int uma_max_ipers;
@@ -959,7 +961,7 @@ startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
 		return (tmps->us_data);
 	}
 	mtx_unlock(&uma_boot_pages_mtx);
-	if (booted == 0)
+	if (booted < UMA_STARTUP2)
 		panic("UMA: Increase vm.boot_pages");
 	/*
 	 * Now that we've booted reset these users to their real allocator.
@@ -1317,9 +1319,10 @@ keg_ctor(void *mem, int size, void *udata, int flags)
 		keg->uk_allocf = uma_small_alloc;
 		keg->uk_freef = uma_small_free;
 #endif
-		if (booted == 0)
+		if (booted < UMA_STARTUP)
 			keg->uk_allocf = startup_alloc;
-	} else if (booted == 0 && (keg->uk_flags & UMA_ZFLAG_INTERNAL))
+	} else if (booted < UMA_STARTUP2 &&
+	    (keg->uk_flags & UMA_ZFLAG_INTERNAL))
 		keg->uk_allocf = startup_alloc;
 
 	/*
@@ -1752,9 +1755,7 @@ uma_startup(void *bootmem, int boot_pages)
 
 	bucket_init();
 
-#if defined(UMA_MD_SMALL_ALLOC) && !defined(UMA_MD_SMALL_ALLOC_NEEDS_VM)
-	booted = 1;
-#endif
+	booted = UMA_STARTUP;
 
 #ifdef UMA_DEBUG
 	printf("UMA startup complete.\n");
@@ -1765,7 +1766,7 @@ uma_startup(void *bootmem, int boot_pages)
 void
 uma_startup2(void)
 {
-	booted = 1;
+	booted = UMA_STARTUP2;
 	bucket_enable();
 #ifdef UMA_DEBUG
 	printf("UMA startup2 complete.\n");
diff --git a/sys/vm/uma_int.h b/sys/vm/uma_int.h
index ae3e2ff..b2b5bac 100644
--- a/sys/vm/uma_int.h
+++ b/sys/vm/uma_int.h
@@ -118,7 +118,7 @@
 #define UMA_SLAB_MASK	(PAGE_SIZE - 1)	/* Mask to get back to the page */
 #define UMA_SLAB_SHIFT	PAGE_SHIFT	/* Number of bits PAGE_MASK */
 
-#define UMA_BOOT_PAGES		48	/* Pages allocated for startup */
+#define UMA_BOOT_PAGES		64	/* Pages allocated for startup */
 
 /* Max waste before going to off page slab management */
 #define UMA_MAX_WASTE	(UMA_SLAB_SIZE / 10)