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| author | Dongli Zhang <dongli.zhang@oracle.com> | 2019-04-12 13:38:26 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2019-04-13 01:44:46 +0200 |
| commit | 53b29c336830db48ad3dc737f88b8c065b1f0851 (patch) | |
| tree | 005f8ea4c317a99f2b583c2fa3b9db21f4eeb0b2 /kernel/dma/swiotlb.c | |
| parent | swiotlb: dump used and total slots when swiotlb buffer is full (diff) | |
| download | linux-53b29c336830db48ad3dc737f88b8c065b1f0851.tar.xz linux-53b29c336830db48ad3dc737f88b8c065b1f0851.zip | |
swiotlb: save io_tlb_used to local variable before leaving critical section
When swiotlb is full, the kernel would print io_tlb_used. However, the
result might be inaccurate at that time because we have left the critical
section protected by spinlock.
Therefore, we backup the io_tlb_used into local variable before leaving
critical section.
Fixes: 83ca25948940 ("swiotlb: dump used and total slots when swiotlb buffer is full")
Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel/dma/swiotlb.c')
| -rw-r--r-- | kernel/dma/swiotlb.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 82c767374c70..38d57218809c 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -445,6 +445,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, unsigned long mask; unsigned long offset_slots; unsigned long max_slots; + unsigned long tmp_io_tlb_used; if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); @@ -531,10 +532,12 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, } while (index != wrap); not_found: + tmp_io_tlb_used = io_tlb_used; + spin_unlock_irqrestore(&io_tlb_lock, flags); if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) - dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu, used %lu\n", - size, io_tlb_nslabs, io_tlb_used); + dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", + size, io_tlb_nslabs, tmp_io_tlb_used); return DMA_MAPPING_ERROR; found: io_tlb_used += nslots; |