On Fri, Nov 28, 2014 at 12:29:07PM +0100, Joerg Roedel wrote: > From: Joerg Roedel <[email protected]> > > Print a warning when all allocation tries have been failed > and the function is about to return NULL. This prepares for > calling the function with __GFP_NOWARN to suppress > allocation failure warnings before all fall-backs have > failed.
This can be quite noisy. Especially the dump-stack. Perhaps have this trigger is the 'verbose' or 'debug' (new) parameter would be added to the 'swiotlb' one? > > Signed-off-by: Joerg Roedel <[email protected]> > --- > lib/swiotlb.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 4abda07..e0e9212 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -655,7 +655,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, > */ > phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE); > if (paddr == SWIOTLB_MAP_ERROR) > - return NULL; > + goto err_warn; > > ret = phys_to_virt(paddr); > dev_addr = phys_to_dma(hwdev, paddr); > @@ -669,7 +669,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, > /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ > swiotlb_tbl_unmap_single(hwdev, paddr, > size, DMA_TO_DEVICE); > - return NULL; > + goto err_warn; > } > } > > @@ -677,6 +677,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, > memset(ret, 0, size); > > return ret; > + > +err_warn: > + pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", > + dev_name(hwdev), size); > + dump_stack(); > + > + return NULL; > } > EXPORT_SYMBOL(swiotlb_alloc_coherent); > > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
