[RFC,PATCH 0/2] dmapool: allocation gfp changes

[Roger Oksanen <roger.oksanen@cs.helsinki.fi>]

Hi,
When introducing dma pools to the e100 driver, it was noticed that allocation
failure warnings were being generated to dmesg when allocations were being
retried (in dma_pool_alloc). Patch #1 changes the allocator to suppress most
warnings (a warning every 10th retry).

Patch #2, which applies on top of patch #1, changes the GFP_ATOMIC
allocation, which allows emergency pool usage, to use the callers GFP_*
flags. This is a scary change that can cause delays in the allocation path,
but is still imho the correct way. Discussion about this approach is welcome!

Additionally, I'm wondering if dma_pool_alloc(..) should be allowed to
fail after a while even when using __GFP_WAIT. Currently it loops forever
if it can't find the requested memory. A quick grep reveals that memory
allocation failures are handled in most drivers using (pci|dma)_pool_alloc.

PATCH 1/2
Don't warn when allowed to retry allocation.

PATCH 2/2
Honor GFP_* flags.

 mm/dmapool.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>