On Thu, 2019-11-21 at 21:55 -0500, Qian Cai wrote: > When running heavy memory pressure workloads, this 5+ old system is > throwing endless warnings below because disk IO is too slow to recover > from swapping. Since the volume from alloc_iova_fast() could be large, > once it calls printk(), it will trigger disk IO (writing to the log > files) and pending softirqs which could cause an infinite loop and make > no progress for days by the ongoimng memory reclaim. This is the counter > part for Intel where the AMD part has already been merged. See the > commit 3d708895325b ("iommu/amd: Silence warnings under memory > pressure"). Since the allocation failure will be reported in > intel_alloc_iova(), so just call printk_ratelimted() there and silence > the one in alloc_iova_mem() to avoid the expensive warn_alloc(). [] > v2: use dev_err_ratelimited() and improve the commit messages. [] > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c [] > @@ -3401,7 +3401,8 @@ static unsigned long intel_alloc_iova(struct device > *dev, > iova_pfn = alloc_iova_fast(&domain->iovad, nrpages, > IOVA_PFN(dma_mask), true); > if (unlikely(!iova_pfn)) { > - dev_err(dev, "Allocating %ld-page iova failed", nrpages); > + dev_err_ratelimited(dev, "Allocating %ld-page iova failed", > + nrpages);
Trivia: This should really have a \n termination on the format string dev_err_ratelimited(dev, "Allocating %ld-page iova failed\n", _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu