Commit 94cc81f9 authored Jun 10, 2015 by Joerg Roedel Committed by Ingo Molnar Jun 11, 2015

swiotlb: Warn on allocation failure in swiotlb_alloc_coherent()



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 - which we'll do to improve kdump behavior.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jörg Rödel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Link: http://lkml.kernel.org/r/1433500202-25531-2-git-send-email-joro@8bytes.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 37ef1647

lib/swiotlb.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -656,7 +656,7 @@ 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);
		@@ -670,7 +670,7 @@ 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;
		}
		}

		@@ -678,6 +678,13 @@ 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);

Admin message