On 11/13/12 7:58 PM, Andrew Morton wrote: > I'm not sure that I really suggested doing this :( You suggested WARN_ON_ONCE(!dev); I changed it to WARN_ON(!dev) and kept the NULL check.. > We know there are a few scruffy drivers which are passing in dev==0. > > Those drivers don't oops because nobody is testing them on NUMA > systems. > > With this patch, the kernel will now cause runtime warnings to be > emitted from those drivers. Even on non-NUMA systems. > > This is a problem! What will happen is that this code will get > released by Linus and will propagate to users mainly via distros and > eventually end-user bug reports will trickle back saying "hey, I got > this warning". Slowly people will fix the scruffy drivers and those > fixes will propagate out from Linus's tree into -stable and then into > distros and then into the end-users hands. > > This is *terribly* inefficient! It's a lot of work for a lot of people > and it involves long delays. > > So let's not do any of that! Let us try to get those scruffy drivers > fixed up *before* we add this warning. > > As a nice side-effect of that work, we can then clean up the dmapool > code so it doesn't need to worry about handling the dev==0 special > case. > > So. To start this off, can you please generate a list of the offending > drivers? Then we can hunt down the maintainers and we'll see what can be > done. I like this plan. Here's the list of drivers that invoke dma_pool_create() with NULL dev, as well as possible fixes, from previous emails. * arch/arm/mach-s3c64xx/dma.c Use dmac->dev for dma_pool_create() in s3c64xx_dma_init1()? Probably need to add ->dma_pool to struct s3c64xx_dmac. * drivers/usb/gadget/amd5536udc.c (2) Use dev->gadget.dev or dev->pdev->dev for dma_pool_create()? Also move the init_dma_pools() call after the assignments in udc_pci_probe(). * drivers/net/wan/ixp4xx_hss.c * drivers/net/ethernet/xscale/ixp4xx_eth.c Use port->netdev->dev for dma_pool_create()? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>