RE: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-23 Thread Marek Szyprowski
Hi Hiroshi, On Thursday, August 23, 2012 8:15 AM Hiroshi Doyu wrote: > On Thu, 23 Aug 2012 07:58:34 +0200 > Marek Szyprowski wrote: > > > Hello, > > > > On Wednesday, August 22, 2012 3:37 PM Hiroshi Doyu wrote: > > > > > KyongHo Cho wrote @ Wed, 22 Aug 2012 14:47:00 > > > +0200: > > > > > > >

Re: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Hiroshi Doyu
Hi, On Thu, 23 Aug 2012 07:58:34 +0200 Marek Szyprowski wrote: > Hello, > > On Wednesday, August 22, 2012 3:37 PM Hiroshi Doyu wrote: > > > KyongHo Cho wrote @ Wed, 22 Aug 2012 14:47:00 > > +0200: > > > > > vzalloc() call in __iommu_alloc_buffer() also causes BUG() in atomic > > > context.

RE: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Marek Szyprowski
Hello, On Wednesday, August 22, 2012 3:37 PM Hiroshi Doyu wrote: > KyongHo Cho wrote @ Wed, 22 Aug 2012 14:47:00 +0200: > > > vzalloc() call in __iommu_alloc_buffer() also causes BUG() in atomic > > context. > > Right. > > I've been thinking that kzalloc() may be enough here, since > vzalloc

Re: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Minchan Kim
On Wed, Aug 22, 2012 at 03:36:48PM +0200, Hiroshi Doyu wrote: > Hi, > > KyongHo Cho wrote @ Wed, 22 Aug 2012 14:47:00 +0200: > > > vzalloc() call in __iommu_alloc_buffer() also causes BUG() in atomic > > context. > > Right. > > I've been thinking that kzalloc() may be enough here, since > vza

Re: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Hiroshi Doyu
Hi, KyongHo Cho wrote @ Wed, 22 Aug 2012 14:47:00 +0200: > vzalloc() call in __iommu_alloc_buffer() also causes BUG() in atomic context. Right. I've been thinking that kzalloc() may be enough here, since vzalloc() was introduced to avoid allocation failure for big chunk of memory, but I think

Re: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Hiroshi Doyu
Marek Szyprowski wrote @ Wed, 22 Aug 2012 14:29:47 +0200: > Hello, > > On Wednesday, August 22, 2012 12:20 PM Hiroshi Doyu wrote: > > > Makes use of the same atomic pool from DMA, and skips kernel page > > mapping which can involves sleep'able operation at allocating a kernel > > page table. >

RE: [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC

2012-08-22 Thread Marek Szyprowski
Hello, On Wednesday, August 22, 2012 12:20 PM Hiroshi Doyu wrote: > Makes use of the same atomic pool from DMA, and skips kernel page > mapping which can involves sleep'able operation at allocating a kernel > page table. > > Signed-off-by: Hiroshi Doyu > --- > arch/arm/mm/dma-mapping.c | 22