From ff6721bf36940d5c0580ad3a04689cd9d01ee3db Mon Sep 17 00:00:00 2001
From: delphij <delphij@FreeBSD.org>
Date: Thu, 14 Aug 2014 05:13:24 +0000
Subject: Re-instate UMA cached backend for 4K - 64K allocations.  New
 consumers like geli(4) uses malloc(9) to allocate temporary buffers that gets
 free'ed shortly, causing frequent TLB shootdown as observed in hwpmc
 supported flame graph.

Discussed with:	jeff, alfred
MFC after:	1 week
---
 sys/kern/kern_malloc.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

(limited to 'sys/kern/kern_malloc.c')

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 464303a..4e8a3bd 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -120,7 +120,7 @@ static int kmemcount;
 #define KMEM_ZBASE	16
 #define KMEM_ZMASK	(KMEM_ZBASE - 1)
 
-#define KMEM_ZMAX	PAGE_SIZE
+#define KMEM_ZMAX	65536
 #define KMEM_ZSIZE	(KMEM_ZMAX >> KMEM_ZSHIFT)
 static uint8_t kmemsize[KMEM_ZSIZE + 1];
 
@@ -151,21 +151,10 @@ struct {
 	{1024, "1024", },
 	{2048, "2048", },
 	{4096, "4096", },
-#if PAGE_SIZE > 4096
 	{8192, "8192", },
-#if PAGE_SIZE > 8192
 	{16384, "16384", },
-#if PAGE_SIZE > 16384
 	{32768, "32768", },
-#if PAGE_SIZE > 32768
 	{65536, "65536", },
-#if PAGE_SIZE > 65536
-#error	"Unsupported PAGE_SIZE"
-#endif	/* 65536 */
-#endif	/* 32768 */
-#endif	/* 16384 */
-#endif	/* 8192 */
-#endif	/* 4096 */
 	{0, NULL},
 };
 
-- 
cgit v1.1


From 5355545756ffaf48c47d9217c4026ab60e9098dc Mon Sep 17 00:00:00 2001
From: delphij <delphij@FreeBSD.org>
Date: Thu, 14 Aug 2014 05:31:39 +0000
Subject: Add a new loader tunable, vm.kmem_zmax which allows a system
 administrator to limit the maximum allocation size that malloc(9) would
 consider using the UMA cache allocator as backend.

Suggested by:	alfred
MFC after:	2 weeks
---
 sys/kern/kern_malloc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

(limited to 'sys/kern/kern_malloc.c')

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 4e8a3bd..c39f143 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -172,6 +172,10 @@ u_long vm_kmem_size;
 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
     "Size of kernel memory");
 
+static u_long kmem_zmax = KMEM_ZMAX;
+SYSCTL_ULONG(_vm, OID_AUTO, kmem_zmax, CTLFLAG_RDTUN, &kmem_zmax, 0,
+    "Maximum allocation size that malloc(9) would use UMA as backend");
+
 static u_long vm_kmem_size_min;
 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
     "Minimum size of kernel memory");
@@ -485,7 +489,7 @@ malloc(unsigned long size, struct malloc_type *mtp, int flags)
 	size = redzone_size_ntor(size);
 #endif
 
-	if (size <= KMEM_ZMAX) {
+	if (size <= kmem_zmax) {
 		mtip = mtp->ks_handle;
 		if (size & KMEM_ZMASK)
 			size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
@@ -776,6 +780,9 @@ mallocinit(void *dummy)
 
 	uma_startup2();
 
+	if (kmem_zmax < PAGE_SIZE || kmem_zmax > KMEM_ZMAX)
+		kmem_zmax = KMEM_ZMAX;
+
 	mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
 #ifdef INVARIANTS
 	    mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
@@ -800,7 +807,7 @@ mallocinit(void *dummy)
 		}		    
 		for (;i <= size; i+= KMEM_ZBASE)
 			kmemsize[i >> KMEM_ZSHIFT] = indx;
-		
+
 	}
 }
 SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_SECOND, mallocinit, NULL);
-- 
cgit v1.1