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![]() Quite often it can be useful to test with dummy or similar devices as a blackhole sink for skbs. Such devices are only equipped with a single txq, but marked as NETIF_F_LLTX as they do not require locking their internal queues on xmit (or implement locking themselves). Therefore, rather use HARD_TX_{UN,}LOCK API, so that NETIF_F_LLTX will be respected. trafgen mmap/TX_RING example against dummy device with config foo: { fill(0xff, 64) } results in the following performance improvements for such scenarios on an ordinary Core i7/2.80GHz: Before: Performance counter stats for 'trafgen -i foo -o du0 -n100000000' (10 runs): 160,975,944,159 instructions:k # 0.55 insns per cycle ( +- 0.09% ) 293,319,390,278 cycles:k # 0.000 GHz ( +- 0.35% ) 192,501,104 branch-misses:k ( +- 1.63% ) 831 context-switches:k ( +- 9.18% ) 7 cpu-migrations:k ( +- 7.40% ) 69,382 cache-misses:k # 0.010 % of all cache refs ( +- 2.18% ) 671,552,021 cache-references:k ( +- 1.29% ) 22.856401569 seconds time elapsed ( +- 0.33% ) After: Performance counter stats for 'trafgen -i foo -o du0 -n100000000' (10 runs): 133,788,739,692 instructions:k # 0.92 insns per cycle ( +- 0.06% ) 145,853,213,256 cycles:k # 0.000 GHz ( +- 0.17% ) 59,867,100 branch-misses:k ( +- 4.72% ) 384 context-switches:k ( +- 3.76% ) 6 cpu-migrations:k ( +- 6.28% ) 70,304 cache-misses:k # 0.077 % of all cache refs ( +- 1.73% ) 90,879,408 cache-references:k ( +- 1.35% ) 11.719372413 seconds time elapsed ( +- 0.24% ) Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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af_packet.c | ||
diag.c | ||
internal.h | ||
Kconfig | ||
Makefile |