| Message ID | 4ABC73C7.20403@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, 2009-09-25 at 16:39 +0900, Tejun Heo wrote: > Hello, > > Sachin Sant wrote: > > <4>PERCPU: chunk 1 relocating -1 -> 18 c0000000db70fb00 > > <c0000000db70fb00:c0000000db70fb00> > > <4>PERCPU: relocated <c000000001120320:c000000001120320> > > <4>PERCPU: chunk 1 relocating 18 -> 16 c0000000db70fb00 > > <c000000001120320:c000000001120320> > > <4>PERCPU: relocated <c000000001120300:c000000001120300> > > <4>PERCPU: chunk 1, alloc pages [0,1) > > <4>PERCPU: chunk 1, map pages [0,1) > > <4>PERCPU: map 0xd00007fffff00000, 1 pages 53544 > > <4>PERCPU: map 0xd00007fffff80000, 1 pages 53545 > > <4>PERCPU: chunk 1, will clear 4096b/unit d00007fffff00000 d00007fffff80000 > > <3>INFO: RCU detected CPU 0 stall (t=1000 jiffies) > > This supports my hypothesis. This is the first area being allocated > from a dynamic chunk and cleared. PFN 53544 and 53545 have been > allocated and successfully mapped to 0xd00007fffff00000 and > 0xd00007fffff80000 using map_kernel_range_noflush() but when those > addresses are actually accessed, we end up with infinite faults. The > fault handler probably thinks that the fault has been handled > correctly but, when the control is returned, the processor faults > again. Benjamin, I'm way out of my depth here, can you please help? Definitely looks like a powerpc mm problem. I'll have a look on monday. Cheers, Ben. > Oh, one more simple experiment. Sachin, does the following patch make > any difference? > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 69511e6..93d29eb 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2102,7 +2102,8 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, > size_t align, gfp_t gfp_mask) > { > const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); > - const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); > + //const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); > + const unsigned long vmalloc_end = vmalloc_start + (512 << 20); > struct vmap_area **vas, *prev, *next; > struct vm_struct **vms; > int area, area2, last_area, term_area; > >
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 69511e6..93d29eb 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2102,7 +2102,8 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, size_t align, gfp_t gfp_mask) { const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); - const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); + //const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); + const unsigned long vmalloc_end = vmalloc_start + (512 << 20); struct vmap_area **vas, *prev, *next; struct vm_struct **vms; int area, area2, last_area, term_area;