diff options
| author | Miquel van Smoorenburg <mikevs@xs4all.net> | 2008-05-28 12:31:25 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-02 14:14:58 +0400 |
| commit | db9f600b96c16bb3c7f094e294fbdd370226ad86 (patch) | |
| tree | ac83fd33678c2e6efecbd7c96503db6cca1549ad /arch/x86 | |
| parent | 75b19b790bec3ebffbf513405b27500e22270cbc (diff) | |
| download | linux-db9f600b96c16bb3c7f094e294fbdd370226ad86.tar.xz | |
x86: pci-dma.c: use __GFP_NO_OOM instead of __GFP_NORETRY
On Wed, 2008-05-28 at 04:47 +0200, Andi Kleen wrote:
> > So... why not just remove the setting of __GFP_NORETRY? Why is it
> > wrong to oom-kill things in this case?
>
> When the 16MB zone overflows (which can be common in some workloads)
> calling the OOM killer is pretty useless because it has barely any
> real user data [only exception would be the "only 16MB" case Alan
> mentioned]. Killing random processes in this case is bad.
>
> I think for 16MB __GFP_NORETRY is ok because there should be
> nothing freeable in there so looping is useless. Only exception would be the
> "only 16MB total" case again but I'm not sure 2.6 supports that at all
> on x86.
>
> On the other hand d_a_c() does more allocations than just 16MB, especially
> on 64bit and the other zones need different strategies.
Okay, so how about this then ?
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index c5ef1af8e79d..069e843f0b93 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -397,9 +397,6 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, if (dev->dma_mask == NULL) return NULL; - /* Don't invoke OOM killer */ - gfp |= __GFP_NORETRY; - #ifdef CONFIG_X86_64 /* Why <=? Even when the mask is smaller than 4GB it is often larger than 16MB and in this case we have a chance of @@ -410,7 +407,9 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, #endif again: - page = dma_alloc_pages(dev, gfp, get_order(size)); + /* Don't invoke OOM killer or retry in lower 16MB DMA zone */ + page = dma_alloc_pages(dev, + (gfp & GFP_DMA) ? gfp | __GFP_NORETRY : gfp, get_order(size)); if (page == NULL) return NULL; |