.

Makefile

@@ -18,14 +18,14 @@ bench_go : t_syspread_go $(XDAT) t_copy_go
 	./t_copy_go >t_copy_go.csv
 
 N	= 10
+Vgo	= 10 11 12 13 14 15 16 17 18 tip
 bench_gov: syspread_test.go
-	>go14.txt; for i in `seq $N`; do go14 test -bench . $< >>go14.txt; done
-	>go15.txt; for i in `seq $N`; do go15 test -bench . $< >>go15.txt; done
-	>go16.txt; for i in `seq $N`; do go16 test -bench . $< >>go16.txt; done
-	>go17.txt; for i in `seq $N`; do go17 test -bench . $< >>go17.txt; done
-	>go18.txt; for i in `seq $N`; do go18 test -bench . $< >>go18.txt; done
-	>gotip.txt; for i in `seq $N`; do go test -bench . $< >>gotip.txt; done
-	benchstat go14.txt go15.txt go16.txt go17.txt go18.txt gotip.txt >gov.txt
+	for V in $(Vgo); do	\
+		echo $$V ...;	\
+		>go$$V.txt; for i in `seq $N`; do go$$V test -bench Pread $< >>go$$V.txt; done	\
+		;	\
+	done
+	benchstat $(patsubst %,go%.txt,$(Vgo)) >gov.txt
 
 t_syspread_go: t_syspread_go.go
 	go build $<

go.txt

+...

go10.txt

+PASS
+BenchmarkReadAt1	10000000	       234 ns/op
+BenchmarkPread1	10000000	       224 ns/op
+ok  	command-line-arguments	5.068s
+PASS
+BenchmarkReadAt1	10000000	       234 ns/op
+BenchmarkPread1	10000000	       224 ns/op
+ok  	command-line-arguments	5.074s
+PASS
+BenchmarkReadAt1	10000000	       234 ns/op
+BenchmarkPread1	10000000	       224 ns/op
+ok  	command-line-arguments	5.071s
+PASS
+BenchmarkReadAt1	10000000	       234 ns/op
+BenchmarkPread1	10000000	       224 ns/op
+ok  	command-line-arguments	5.066s
+PASS
+BenchmarkReadAt1	10000000	       235 ns/op
+BenchmarkPread1	10000000	       224 ns/op
+ok  	command-line-arguments	5.067s
+PASS
+BenchmarkReadAt1	10000000	       234 ns/op
+BenchmarkPread1	10000000	       227 ns/op
+ok  	command-line-arguments	5.088s
+PASS
+BenchmarkReadAt1	10000000	       238 ns/op
+BenchmarkPread1	10000000	       228 ns/op
+ok  	command-line-arguments	5.152s
+PASS
+BenchmarkReadAt1	10000000	       241 ns/op
+BenchmarkPread1	10000000	       229 ns/op
+ok  	command-line-arguments	5.183s
+PASS
+BenchmarkReadAt1	10000000	       238 ns/op
+BenchmarkPread1	10000000	       227 ns/op
+ok  	command-line-arguments	5.147s
+PASS
+BenchmarkReadAt1	10000000	       239 ns/op
+BenchmarkPread1	10000000	       229 ns/op
+ok  	command-line-arguments	5.170s

go11.txt

+PASS
+BenchmarkReadAt1	10000000	       242 ns/op
+BenchmarkPread1	10000000	       232 ns/op
+ok  	command-line-arguments	5.241s
+PASS
+BenchmarkReadAt1	10000000	       239 ns/op
+BenchmarkPread1	10000000	       229 ns/op
+ok  	command-line-arguments	5.180s
+PASS
+BenchmarkReadAt1	10000000	       242 ns/op
+BenchmarkPread1	10000000	       232 ns/op
+ok  	command-line-arguments	5.237s
+PASS
+BenchmarkReadAt1	10000000	       239 ns/op
+BenchmarkPread1	10000000	       229 ns/op
+ok  	command-line-arguments	5.181s
+PASS
+BenchmarkReadAt1	10000000	       241 ns/op
+BenchmarkPread1	10000000	       233 ns/op
+ok  	command-line-arguments	5.243s
+PASS
+BenchmarkReadAt1	10000000	       242 ns/op
+BenchmarkPread1	10000000	       230 ns/op
+ok  	command-line-arguments	5.212s
+PASS
+BenchmarkReadAt1	10000000	       243 ns/op
+BenchmarkPread1	10000000	       230 ns/op
+ok  	command-line-arguments	5.225s
+PASS
+BenchmarkReadAt1	10000000	       241 ns/op
+BenchmarkPread1	10000000	       234 ns/op
+ok  	command-line-arguments	5.243s
+PASS
+BenchmarkReadAt1	10000000	       239 ns/op
+BenchmarkPread1	10000000	       232 ns/op
+ok  	command-line-arguments	5.212s
+PASS
+BenchmarkReadAt1	10000000	       245 ns/op
+BenchmarkPread1	10000000	       231 ns/op
+ok  	command-line-arguments	5.274s

go12.txt

+PASS
+BenchmarkReadAt1	10000000	       254 ns/op
+BenchmarkPread1	10000000	       242 ns/op
+ok  	command-line-arguments	5.490s
+PASS
+BenchmarkReadAt1	10000000	       251 ns/op
+BenchmarkPread1	10000000	       240 ns/op
+ok  	command-line-arguments	5.425s
+PASS
+BenchmarkReadAt1	10000000	       253 ns/op
+BenchmarkPread1	10000000	       244 ns/op
+ok  	command-line-arguments	5.489s
+PASS
+BenchmarkReadAt1	10000000	       251 ns/op
+BenchmarkPread1	10000000	       243 ns/op
+ok  	command-line-arguments	5.463s
+PASS
+BenchmarkReadAt1	10000000	       254 ns/op
+BenchmarkPread1	10000000	       240 ns/op
+ok  	command-line-arguments	5.464s
+PASS
+BenchmarkReadAt1	10000000	       252 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.452s
+PASS
+BenchmarkReadAt1	10000000	       251 ns/op
+BenchmarkPread1	10000000	       242 ns/op
+ok  	command-line-arguments	5.450s
+PASS
+BenchmarkReadAt1	10000000	       253 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.458s
+PASS
+BenchmarkReadAt1	10000000	       251 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.433s
+PASS
+BenchmarkReadAt1	10000000	       249 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.421s

go13.txt

+PASS
+BenchmarkReadAt1	10000000	       250 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.434s
+PASS
+BenchmarkReadAt1	10000000	       257 ns/op
+BenchmarkPread1	10000000	       243 ns/op
+ok  	command-line-arguments	5.526s
+PASS
+BenchmarkReadAt1	10000000	       254 ns/op
+BenchmarkPread1	10000000	       242 ns/op
+ok  	command-line-arguments	5.488s
+PASS
+BenchmarkReadAt1	10000000	       259 ns/op
+BenchmarkPread1	10000000	       243 ns/op
+ok  	command-line-arguments	5.538s
+PASS
+BenchmarkReadAt1	10000000	       252 ns/op
+BenchmarkPread1	10000000	       241 ns/op
+ok  	command-line-arguments	5.459s
+PASS
+BenchmarkReadAt1	10000000	       253 ns/op
+BenchmarkPread1	10000000	       240 ns/op
+ok  	command-line-arguments	5.444s
+PASS
+BenchmarkReadAt1	10000000	       252 ns/op
+BenchmarkPread1	10000000	       238 ns/op
+ok  	command-line-arguments	5.425s
+PASS
+BenchmarkReadAt1	10000000	       252 ns/op
+BenchmarkPread1	10000000	       239 ns/op
+ok  	command-line-arguments	5.421s
+PASS
+BenchmarkReadAt1	10000000	       250 ns/op
+BenchmarkPread1	10000000	       240 ns/op
+ok  	command-line-arguments	5.433s
+PASS
+BenchmarkReadAt1	10000000	       251 ns/op
+BenchmarkPread1	10000000	       237 ns/op
+ok  	command-line-arguments	5.408s

go14.txt

 PASS
-BenchmarkReadAt1	 5000000	       270 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.211s
+BenchmarkReadAt1	 5000000	       271 ns/op
+BenchmarkPread1	 5000000	       262 ns/op
+ok  	command-line-arguments	3.231s
 PASS
-BenchmarkReadAt1	 5000000	       268 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.189s
+BenchmarkReadAt1	 5000000	       279 ns/op
+BenchmarkPread1	 5000000	       261 ns/op
+ok  	command-line-arguments	3.276s
 PASS
-BenchmarkReadAt1	 5000000	       269 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.192s
+BenchmarkReadAt1	 5000000	       270 ns/op
+BenchmarkPread1	 5000000	       272 ns/op
+ok  	command-line-arguments	3.270s
 PASS
-BenchmarkReadAt1	 5000000	       268 ns/op
+BenchmarkReadAt1	 5000000	       273 ns/op
 BenchmarkPread1	 5000000	       259 ns/op
-ok  	command-line-arguments	3.188s
+ok  	command-line-arguments	3.219s
 PASS
-BenchmarkReadAt1	 5000000	       268 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.186s
+BenchmarkReadAt1	 5000000	       274 ns/op
+BenchmarkPread1	 5000000	       264 ns/op
+ok  	command-line-arguments	3.255s
 PASS
-BenchmarkReadAt1	 5000000	       267 ns/op
-BenchmarkPread1	 5000000	       260 ns/op
-ok  	command-line-arguments	3.193s
+BenchmarkReadAt1	 5000000	       273 ns/op
+BenchmarkPread1	 5000000	       265 ns/op
+ok  	command-line-arguments	3.254s
 PASS
-BenchmarkReadAt1	 5000000	       272 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.203s
+BenchmarkReadAt1	 5000000	       274 ns/op
+BenchmarkPread1	 5000000	       261 ns/op
+ok  	command-line-arguments	3.236s
 PASS
-BenchmarkReadAt1	 5000000	       268 ns/op
-BenchmarkPread1	 5000000	       259 ns/op
-ok  	command-line-arguments	3.192s
+BenchmarkReadAt1	 5000000	       271 ns/op
+BenchmarkPread1	 5000000	       263 ns/op
+ok  	command-line-arguments	3.229s
 PASS
-BenchmarkReadAt1	 5000000	       267 ns/op
-BenchmarkPread1	 5000000	       260 ns/op
-ok  	command-line-arguments	3.191s
+BenchmarkReadAt1	 5000000	       305 ns/op
+BenchmarkPread1	 5000000	       356 ns/op
+ok  	command-line-arguments	3.946s
 PASS
-BenchmarkReadAt1	 5000000	       269 ns/op
-BenchmarkPread1	 5000000	       258 ns/op
-ok  	command-line-arguments	3.187s
+BenchmarkReadAt1	 5000000	       285 ns/op
+BenchmarkPread1	 5000000	       259 ns/op
+ok  	command-line-arguments	3.320s

go15.txt

 PASS
-BenchmarkReadAt1-4	 5000000	       276 ns/op
+BenchmarkReadAt1-4	 5000000	       286 ns/op
 BenchmarkPread1-4 	 5000000	       266 ns/op
-ok  	command-line-arguments	3.265s
+ok  	command-line-arguments	3.325s
 PASS
-BenchmarkReadAt1-4	 5000000	       276 ns/op
-BenchmarkPread1-4 	 5000000	       263 ns/op
-ok  	command-line-arguments	3.251s
+BenchmarkReadAt1-4	 5000000	       277 ns/op
+BenchmarkPread1-4 	 5000000	       267 ns/op
+ok  	command-line-arguments	3.286s
 PASS
-BenchmarkReadAt1-4	 5000000	       272 ns/op
-BenchmarkPread1-4 	 5000000	       261 ns/op
-ok  	command-line-arguments	3.225s
+BenchmarkReadAt1-4	 5000000	       280 ns/op
+BenchmarkPread1-4 	 5000000	       266 ns/op
+ok  	command-line-arguments	3.302s
 PASS
 BenchmarkReadAt1-4	 5000000	       275 ns/op
-BenchmarkPread1-4 	 5000000	       261 ns/op
-ok  	command-line-arguments	3.237s
-PASS
-BenchmarkReadAt1-4	 5000000	       274 ns/op
 BenchmarkPread1-4 	 5000000	       264 ns/op
-ok  	command-line-arguments	3.250s
-PASS
-BenchmarkReadAt1-4	 5000000	       275 ns/op
-BenchmarkPread1-4 	 5000000	       261 ns/op
-ok  	command-line-arguments	3.244s
+ok  	command-line-arguments	3.258s
 PASS
-BenchmarkReadAt1-4	 5000000	       272 ns/op
-BenchmarkPread1-4 	 5000000	       260 ns/op
-ok  	command-line-arguments	3.224s
+BenchmarkReadAt1-4	 5000000	       278 ns/op
+BenchmarkPread1-4 	 5000000	       266 ns/op
+ok  	command-line-arguments	3.287s
 PASS
-BenchmarkReadAt1-4	 5000000	       274 ns/op
-BenchmarkPread1-4 	 5000000	       261 ns/op
-ok  	command-line-arguments	3.235s
+BenchmarkReadAt1-4	 5000000	       276 ns/op
+BenchmarkPread1-4 	 5000000	       264 ns/op
+ok  	command-line-arguments	3.263s
 PASS
-BenchmarkReadAt1-4	 5000000	       273 ns/op
+BenchmarkReadAt1-4	 5000000	       279 ns/op
 BenchmarkPread1-4 	 5000000	       265 ns/op
-ok  	command-line-arguments	3.244s
+ok  	command-line-arguments	3.279s
+PASS
+BenchmarkReadAt1-4	 5000000	       277 ns/op
+BenchmarkPread1-4 	 5000000	       263 ns/op
+ok  	command-line-arguments	3.268s
+PASS
+BenchmarkReadAt1-4	 5000000	       278 ns/op
+BenchmarkPread1-4 	 5000000	       264 ns/op
+ok  	command-line-arguments	3.281s
 PASS
-BenchmarkReadAt1-4	 5000000	       273 ns/op
-BenchmarkPread1-4 	 5000000	       261 ns/op
-ok  	command-line-arguments	3.233s
+BenchmarkReadAt1-4	 5000000	       279 ns/op
+BenchmarkPread1-4 	 5000000	       267 ns/op
+ok  	command-line-arguments	3.296s

go16.txt

 PASS
-BenchmarkReadAt1-4	 5000000	       278 ns/op
-BenchmarkPread1-4 	 5000000	       268 ns/op
-ok  	command-line-arguments	3.304s
+BenchmarkReadAt1-4	 5000000	       282 ns/op
+BenchmarkPread1-4 	 5000000	       269 ns/op
+ok  	command-line-arguments	3.332s
 PASS
-BenchmarkReadAt1-4	 5000000	       278 ns/op
-BenchmarkPread1-4 	 5000000	       278 ns/op
-ok  	command-line-arguments	3.358s
+BenchmarkReadAt1-4	 5000000	       277 ns/op
+BenchmarkPread1-4 	 5000000	       270 ns/op
+ok  	command-line-arguments	3.300s
 PASS
-BenchmarkReadAt1-4	 5000000	       278 ns/op
-BenchmarkPread1-4 	 5000000	       272 ns/op
-ok  	command-line-arguments	3.322s
+BenchmarkReadAt1-4	 5000000	       279 ns/op
+BenchmarkPread1-4 	 5000000	       267 ns/op
+ok  	command-line-arguments	3.300s
 PASS
-BenchmarkReadAt1-4	 5000000	       276 ns/op
-BenchmarkPread1-4 	 5000000	       265 ns/op
-ok  	command-line-arguments	3.265s
+BenchmarkReadAt1-4	 5000000	       284 ns/op
+BenchmarkPread1-4 	 5000000	       273 ns/op
+ok  	command-line-arguments	3.356s
 PASS
-BenchmarkReadAt1-4	 5000000	       281 ns/op
-BenchmarkPread1-4 	 5000000	       267 ns/op
-ok  	command-line-arguments	3.307s
+BenchmarkReadAt1-4	 5000000	       283 ns/op
+BenchmarkPread1-4 	 5000000	       271 ns/op
+ok  	command-line-arguments	3.340s
 PASS
-BenchmarkReadAt1-4	 5000000	       276 ns/op
-BenchmarkPread1-4 	 5000000	       266 ns/op
-ok  	command-line-arguments	3.276s
+BenchmarkReadAt1-4	 5000000	       285 ns/op
+BenchmarkPread1-4 	 5000000	       280 ns/op
+ok  	command-line-arguments	3.409s
 PASS
-BenchmarkReadAt1-4	 5000000	       279 ns/op
-BenchmarkPread1-4 	 5000000	       266 ns/op
-ok  	command-line-arguments	3.294s
+BenchmarkReadAt1-4	 5000000	       281 ns/op
+BenchmarkPread1-4 	 5000000	       273 ns/op
+ok  	command-line-arguments	3.346s
 PASS
-BenchmarkReadAt1-4	 5000000	       277 ns/op
-BenchmarkPread1-4 	 5000000	       266 ns/op
-ok  	command-line-arguments	3.285s
+BenchmarkReadAt1-4	 5000000	       281 ns/op
+BenchmarkPread1-4 	 5000000	       271 ns/op
+ok  	command-line-arguments	3.333s
 PASS
-BenchmarkReadAt1-4	 5000000	       276 ns/op
-BenchmarkPread1-4 	 5000000	       266 ns/op
-ok  	command-line-arguments	3.281s
+BenchmarkReadAt1-4	 5000000	       280 ns/op
+BenchmarkPread1-4 	 5000000	       269 ns/op
+ok  	command-line-arguments	3.318s
 PASS
-BenchmarkReadAt1-4	 5000000	       275 ns/op
-BenchmarkPread1-4 	 5000000	       264 ns/op
-ok  	command-line-arguments	3.261s
+BenchmarkReadAt1-4	 5000000	       280 ns/op
+BenchmarkPread1-4 	 5000000	       273 ns/op
+ok  	command-line-arguments	3.343s

go17.txt

-BenchmarkReadAt1-4   	 5000000	       272 ns/op
-BenchmarkPread1-4    	 5000000	       260 ns/op
+BenchmarkReadAt1-4   	 5000000	       273 ns/op
+BenchmarkPread1-4    	 5000000	       262 ns/op
 PASS
-ok  	command-line-arguments	3.216s
-BenchmarkReadAt1-4   	 5000000	       276 ns/op
-BenchmarkPread1-4    	 5000000	       266 ns/op
+ok  	command-line-arguments	3.232s
+BenchmarkReadAt1-4   	 5000000	       277 ns/op
+BenchmarkPread1-4    	 5000000	       262 ns/op
 PASS
-ok  	command-line-arguments	3.271s
+ok  	command-line-arguments	3.258s
 BenchmarkReadAt1-4   	 5000000	       272 ns/op
-BenchmarkPread1-4    	 5000000	       260 ns/op
+BenchmarkPread1-4    	 5000000	       264 ns/op
 PASS
-ok  	command-line-arguments	3.210s
-BenchmarkReadAt1-4   	 5000000	       274 ns/op
-BenchmarkPread1-4    	 5000000	       261 ns/op
+ok  	command-line-arguments	3.233s
+BenchmarkReadAt1-4   	 5000000	       282 ns/op
+BenchmarkPread1-4    	 5000000	       265 ns/op
 PASS
-ok  	command-line-arguments	3.230s
-BenchmarkReadAt1-4   	 5000000	       276 ns/op
-BenchmarkPread1-4    	 5000000	       267 ns/op
-PASS
-ok  	command-line-arguments	3.284s
-BenchmarkReadAt1-4   	 5000000	       274 ns/op
-BenchmarkPread1-4    	 5000000	       263 ns/op
+ok  	command-line-arguments	3.299s
+BenchmarkReadAt1-4   	 5000000	       278 ns/op
+BenchmarkPread1-4    	 5000000	       265 ns/op
 PASS
-ok  	command-line-arguments	3.239s
-BenchmarkReadAt1-4   	 5000000	       275 ns/op
-BenchmarkPread1-4    	 5000000	       260 ns/op
+ok  	command-line-arguments	3.276s
+BenchmarkReadAt1-4   	 5000000	       277 ns/op
+BenchmarkPread1-4    	 5000000	       262 ns/op
 PASS
-ok  	command-line-arguments	3.231s
-BenchmarkReadAt1-4   	 5000000	       272 ns/op
-BenchmarkPread1-4    	 5000000	       260 ns/op
+ok  	command-line-arguments	3.246s
+BenchmarkReadAt1-4   	 5000000	       277 ns/op
+BenchmarkPread1-4    	 5000000	       266 ns/op
 PASS
-ok  	command-line-arguments	3.216s
+ok  	command-line-arguments	3.277s
 BenchmarkReadAt1-4   	 5000000	       274 ns/op
-BenchmarkPread1-4    	 5000000	       262 ns/op
+BenchmarkPread1-4    	 5000000	       263 ns/op
 PASS
-ok  	command-line-arguments	3.243s
+ok  	command-line-arguments	3.241s
 BenchmarkReadAt1-4   	 5000000	       273 ns/op
 BenchmarkPread1-4    	 5000000	       261 ns/op
 PASS
-ok  	command-line-arguments	3.221s
+ok  	command-line-arguments	3.226s
+BenchmarkReadAt1-4   	 5000000	       275 ns/op
+BenchmarkPread1-4    	 5000000	       265 ns/op
+PASS
+ok  	command-line-arguments	3.258s

go18.txt

 BenchmarkReadAt1-4   	 5000000	       265 ns/op
-BenchmarkPread1-4    	 5000000	       254 ns/op
+BenchmarkPread1-4    	 5000000	       255 ns/op
 PASS
-ok  	command-line-arguments	3.131s
-BenchmarkReadAt1-4   	 5000000	       265 ns/op
-BenchmarkPread1-4    	 5000000	       254 ns/op
+ok  	command-line-arguments	3.145s
+BenchmarkReadAt1-4   	 5000000	       267 ns/op
+BenchmarkPread1-4    	 5000000	       255 ns/op
 PASS
-ok  	command-line-arguments	3.133s
-BenchmarkReadAt1-4   	 5000000	       262 ns/op
+ok  	command-line-arguments	3.143s
+BenchmarkReadAt1-4   	 5000000	       263 ns/op
 BenchmarkPread1-4    	 5000000	       253 ns/op
 PASS
-ok  	command-line-arguments	3.115s
-BenchmarkReadAt1-4   	 5000000	       262 ns/op
-BenchmarkPread1-4    	 5000000	       251 ns/op
+ok  	command-line-arguments	3.117s
+BenchmarkReadAt1-4   	 5000000	       261 ns/op
+BenchmarkPread1-4    	 5000000	       257 ns/op
 PASS
-ok  	command-line-arguments	3.100s
-BenchmarkReadAt1-4   	 5000000	       264 ns/op
-BenchmarkPread1-4    	 5000000	       253 ns/op
+ok  	command-line-arguments	3.125s
+BenchmarkReadAt1-4   	 5000000	       267 ns/op
+BenchmarkPread1-4    	 5000000	       257 ns/op
 PASS
-ok  	command-line-arguments	3.127s
-BenchmarkReadAt1-4   	 5000000	       262 ns/op
-BenchmarkPread1-4    	 5000000	       252 ns/op
+ok  	command-line-arguments	3.162s
+BenchmarkReadAt1-4   	 5000000	       263 ns/op
+BenchmarkPread1-4    	 5000000	       259 ns/op
 PASS
-ok  	command-line-arguments	3.105s
-BenchmarkReadAt1-4   	 5000000	       262 ns/op
-BenchmarkPread1-4    	 5000000	       249 ns/op
+ok  	command-line-arguments	3.151s
+BenchmarkReadAt1-4   	 5000000	       272 ns/op
+BenchmarkPread1-4    	 5000000	       256 ns/op
 PASS
-ok  	command-line-arguments	3.087s
-BenchmarkReadAt1-4   	 5000000	       262 ns/op
+ok  	command-line-arguments	3.178s
+BenchmarkReadAt1-4   	 5000000	       261 ns/op
 BenchmarkPread1-4    	 5000000	       253 ns/op
 PASS
-ok  	command-line-arguments	3.108s
-BenchmarkReadAt1-4   	 5000000	       263 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
+ok  	command-line-arguments	3.105s
+BenchmarkReadAt1-4   	 5000000	       265 ns/op
+BenchmarkPread1-4    	 5000000	       260 ns/op
 PASS
-ok  	command-line-arguments	3.098s
-BenchmarkReadAt1-4   	 5000000	       261 ns/op
-BenchmarkPread1-4    	 5000000	       251 ns/op
+ok  	command-line-arguments	3.163s
+BenchmarkReadAt1-4   	 5000000	       265 ns/op
+BenchmarkPread1-4    	 5000000	       254 ns/op
 PASS
-ok  	command-line-arguments	3.097s
+ok  	command-line-arguments	3.134s

gotip.txt

 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       323 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
-PASS
-ok  	command-line-arguments	3.455s
-goos: linux
-goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       322 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
+BenchmarkReadAt1-4   	 5000000	       330 ns/op
+BenchmarkPread1-4    	 5000000	       254 ns/op
 PASS
-ok  	command-line-arguments	3.453s
+ok  	command-line-arguments	3.513s
 goos: linux
 goarch: amd64
 BenchmarkReadAt1-4   	 5000000	       327 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
+BenchmarkPread1-4    	 5000000	       252 ns/op
 PASS
-ok  	command-line-arguments	3.485s
+ok  	command-line-arguments	3.493s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       323 ns/op
-BenchmarkPread1-4    	 5000000	       251 ns/op
+BenchmarkReadAt1-4   	 5000000	       325 ns/op
+BenchmarkPread1-4    	 5000000	       252 ns/op
 PASS
-ok  	command-line-arguments	3.465s
+ok  	command-line-arguments	3.482s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       322 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
+BenchmarkReadAt1-4   	 5000000	       324 ns/op
+BenchmarkPread1-4    	 5000000	       254 ns/op
 PASS
-ok  	command-line-arguments	3.452s
+ok  	command-line-arguments	3.486s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       323 ns/op
-BenchmarkPread1-4    	 5000000	       252 ns/op
+BenchmarkReadAt1-4   	 5000000	       327 ns/op
+BenchmarkPread1-4    	 5000000	       253 ns/op
 PASS
-ok  	command-line-arguments	3.467s
+ok  	command-line-arguments	3.501s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       323 ns/op
-BenchmarkPread1-4    	 5000000	       250 ns/op
+BenchmarkReadAt1-4   	 5000000	       328 ns/op
+BenchmarkPread1-4    	 5000000	       257 ns/op
 PASS
-ok  	command-line-arguments	3.465s
+ok  	command-line-arguments	3.526s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       323 ns/op
+BenchmarkReadAt1-4   	 5000000	       325 ns/op
 BenchmarkPread1-4    	 5000000	       250 ns/op
 PASS
-ok  	command-line-arguments	3.461s
+ok  	command-line-arguments	3.478s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       322 ns/op
+BenchmarkReadAt1-4   	 5000000	       328 ns/op
 BenchmarkPread1-4    	 5000000	       251 ns/op
 PASS
-ok  	command-line-arguments	3.461s
+ok  	command-line-arguments	3.508s
 goos: linux
 goarch: amd64
-BenchmarkReadAt1-4   	 5000000	       325 ns/op
+BenchmarkReadAt1-4   	 5000000	       329 ns/op
 BenchmarkPread1-4    	 5000000	       252 ns/op
 PASS
-ok  	command-line-arguments	3.483s
+ok  	command-line-arguments	3.496s
+goos: linux
+goarch: amd64
+BenchmarkReadAt1-4   	 5000000	       327 ns/op
+BenchmarkPread1-4    	 5000000	       254 ns/op
+PASS
+ok  	command-line-arguments	3.507s

gov.txt

-name \ time/op  go14.txt    go15.txt    go16.txt    go17.txt    go18.txt    gotip.txt
-ReadAt1         268ns ± 1%
-Pread1          259ns ± 1%
-ReadAt1-4                   274ns ± 1%  277ns ± 1%  274ns ± 1%  263ns ± 1%  323ns ± 0%
-Pread1-4                    262ns ± 1%  266ns ± 1%  262ns ± 2%  252ns ± 1%  251ns ± 1%
+name \ time/op  go10.txt    go11.txt    go12.txt    go13.txt    go14.txt    go15.txt    go16.txt    go17.txt    go18.txt    gotip.txt
+ReadAt1         236ns ± 2%  241ns ± 2%  252ns ± 1%  253ns ± 2%  274ns ± 4%
+Pread1          226ns ± 1%  231ns ± 1%  241ns ± 1%  240ns ± 1%  263ns ± 3%
+ReadAt1-4                                                                   278ns ± 1%  281ns ± 1%  276ns ± 2%  265ns ± 3%  327ns ± 1%
+Pread1-4                                                                    265ns ± 1%  271ns ± 1%  264ns ± 1%  256ns ± 2%  253ns ± 2%

syspread_test.go

@@ -32,7 +32,7 @@ func xreadat(f *os.File, buf []byte, offset int64) {
 }
 
 // setupXdat4K setups /dev/shm/x.dat with 4K content
-func setupXdat4K(t testing.TB) *os.File {
+func setupXdat4K(t interface {Fatal(...interface{})} /* = testing.TB */) *os.File {
 	// setup 4K file on a tmpfs
 	f, err := os.Create("/dev/shm/x.dat")
 	if err != nil {