d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Reintroduce UMA_SLAB_KMAP; however, change its spelling to

Browse Source 
UMA_SLAB_KERNEL for consistency with its sibling UMA_SLAB_KMEM.
(UMA_SLAB_KMAP met its original demise in revision 1.30 of
vm/uma_core.c.)  UMA_SLAB_KERNEL is now required by the jumbo frame
allocators.  Without it, UMA cannot correctly return pages from the
jumbo frame zones to the VM system because it resets the pages' object
field to NULL instead of the kernel object.  In more detail, the jumbo
frame zones are created with the option UMA_ZONE_REFCNT.  This causes
UMA to overwrite the pages' object field with the address of the slab.
However, when UMA wants to release these pages, it doesn't know how to
restore the object field, so it sets it to NULL.  This change teaches
UMA how to reset the object field to the kernel object.

Crashes reported by: kris
Fix tested by: kris
Fix discussed with: jeff
MFC after: 6 weeks
This commit is contained in:
Alan Cox 2008-04-04 18:41:12 +00:00
parent 1ff6c09714
commit 7630c26507
4 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/i386/i386/pmap.c
View File

@ -561,7 +561,9 @@ static MALLOC_DEFINE(M_PMAPPDPT, "pmap", "pmap pdpt");
static void *
pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
{
*flags = UMA_SLAB_PRIV;
/* Inform UMA that this allocator uses kernel_map/object. */
*flags = UMA_SLAB_KERNEL;
return (contigmalloc(PAGE_SIZE, M_PMAPPDPT, 0, 0x0ULL, 0xffffffffULL,
1, 0));
}

3
sys/kern/kern_mbuf.c
View File

@ -352,7 +352,8 @@ static void *
mbuf_jumbo_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
{
*flags = UMA_SLAB_PRIV;
/* Inform UMA that this allocator uses kernel_map/object. */
*flags = UMA_SLAB_KERNEL;
return (contigmalloc(bytes, M_JUMBOFRAME, wait, (vm_paddr_t)0,
~(vm_paddr_t)0, 1, 0));
}

1
sys/vm/uma.h
View File

@ -488,6 +488,7 @@ void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
*/
#define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
#define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
#define UMA_SLAB_KERNEL 0x04 /* Slab alloced from kernel_map */
#define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
#define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
#define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */

4
sys/vm/uma_core.c
View File

@ -751,6 +751,8 @@ zone_drain(uma_zone_t zone)
if (flags & UMA_SLAB_KMEM)
obj = kmem_object;
else if (flags & UMA_SLAB_KERNEL)
obj = kernel_object;
else
obj = NULL;
for (i = 0; i < keg->uk_ppera; i++)
@ -871,6 +873,8 @@ slab_zalloc(uma_zone_t zone, int wait)
if (flags & UMA_SLAB_KMEM)
obj = kmem_object;
else if (flags & UMA_SLAB_KERNEL)
obj = kernel_object;
else
obj = NULL;
for (i = 0; i < keg->uk_ppera; i++)