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authorPetr Tesarik <petr.tesarik.ext@huawei.com>2023-04-20 11:58:58 +0200
committerChristoph Hellwig <hch@lst.de>2023-04-20 14:51:41 +0200
commitec274aff21b6a94c7973384ca80a503c1bc3b173 (patch)
tree03fd86f07ec5b3585fda7e993e9443f75ad86b63 /include/linux/swiotlb.h
parent8b0977ecc8b30a30966e76fcb64cef5041626b02 (diff)
swiotlb: Omit total_used and used_hiwater if !CONFIG_DEBUG_FS
The tracking of used_hiwater adds an atomic operation to the hot path. This is acceptable only when debugging the kernel. To make sure that the fields can never be used by mistake, do not even include them in struct io_tlb_mem if CONFIG_DEBUG_FS is not set. The build fails after doing that. To fix it, it is necessary to remove all code specific to debugfs and instead provide a stub implementation of swiotlb_create_debugfs_files(). As a bonus, this change allows to remove one __maybe_unused attribute. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/linux/swiotlb.h')
-rw-r--r--include/linux/swiotlb.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 6dc4598d2260..44767844e12b 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -107,8 +107,10 @@ struct io_tlb_mem {
unsigned int area_nslabs;
struct io_tlb_area *areas;
struct io_tlb_slot *slots;
+#ifdef CONFIG_DEBUG_FS
atomic_long_t total_used;
atomic_long_t used_hiwater;
+#endif
};
extern struct io_tlb_mem io_tlb_default_mem;