Commit 5e76f564 authored Oct 30, 2019 by Eric Dumazet Committed by Christoph Hellwig Nov 11, 2019

dma-debug: increase HASH_SIZE



With modern NIC, it is not unusual having about ~256,000 active dma
mappings and a hash size of 1024 buckets is too small.

Forcing full cache line per bucket does not seem useful, especially now
that we have contention on free_entries_lock for allocations and freeing
of entries.  Better use the space to fit more buckets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

parent d3694f30

kernel/dma/debug.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -27,7 +27,7 @@

		#include <asm/sections.h>

		#define HASH_SIZE 1024ULL
		#define HASH_SIZE 16384ULL
		#define HASH_FN_SHIFT 13
		#define HASH_FN_MASK (HASH_SIZE - 1)

		@@ -87,7 +87,7 @@ typedef bool (match_fn)(struct dma_debug_entry , struct dma_debug_entry *);
		struct hash_bucket {
		struct list_head list;
		spinlock_t lock;
		} ____cacheline_aligned_in_smp;
		};

		/* Hash list to save the allocated dma addresses */
		static struct hash_bucket dma_entry_hash[HASH_SIZE];

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