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| author | Dexuan Cui <decui@microsoft.com> | 2024-03-29 12:28:09 -0700 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2024-04-02 17:08:09 +0200 |
| commit | a1255ccab8ecee89905ddb12161139b0d878a7f2 (patch) | |
| tree | 96303c8896872d3b3bb600b3774f7bcfba78f3e6 /kernel | |
| parent | e8068f2d756d57a5206fa3180ade365a8c12ed85 (diff) | |
| download | linux-stable-a1255ccab8ecee89905ddb12161139b0d878a7f2.tar.gz linux-stable-a1255ccab8ecee89905ddb12161139b0d878a7f2.tar.bz2 linux-stable-a1255ccab8ecee89905ddb12161139b0d878a7f2.zip | |
swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files()
Sometimes the readout of /sys/kernel/debug/swiotlb/io_tlb_used and
io_tlb_used_hiwater can be a huge number (e.g. 18446744073709551615),
which is actually a negative number if we use "%ld" to print the number.
When swiotlb_create_default_debugfs() is running from late_initcall,
mem->total_used may already be non-zero, because the storage driver
may have already started to perform I/O operations: if the storage
driver is built-in, its probe() callback is called before late_initcall.
swiotlb_create_debugfs_files() should not blindly set mem->total_used
and mem->used_hiwater to 0; actually it doesn't have to initialize the
fields at all, because the fields, as part of the global struct
io_tlb_default_mem, have been implicitly initialized to zero.
Also don't explicitly set mem->transient_nslabs to 0.
Fixes: 8b0977ecc8b3 ("swiotlb: track and report io_tlb_used high water marks in debugfs")
Fixes: 02e765697038 ("swiotlb: add debugfs to track swiotlb transient pool usage")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/dma/swiotlb.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index d57c8837c813..a5e0dfc44d24 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1676,9 +1676,6 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_hiwater, io_tlb_hiwater_get, static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, const char *dirname) { - atomic_long_set(&mem->total_used, 0); - atomic_long_set(&mem->used_hiwater, 0); - mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs); if (!mem->nslabs) return; @@ -1689,7 +1686,6 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, debugfs_create_file("io_tlb_used_hiwater", 0600, mem->debugfs, mem, &fops_io_tlb_hiwater); #ifdef CONFIG_SWIOTLB_DYNAMIC - atomic_long_set(&mem->transient_nslabs, 0); debugfs_create_file("io_tlb_transient_nslabs", 0400, mem->debugfs, mem, &fops_io_tlb_transient_used); #endif |