.

Makefile

@@ -9,6 +9,10 @@ $(XDAT)	:
 
 bench	: bench_c bench_go
 
+bench_copy: t_copy_c t_copy_go
+	./t_copy_c >t_copy_c.csv
+	./t_copy_go >t_copy_go.csv
+
 bench_c	: t_syspread_c $(XDAT) t_copy_c
 	./t_syspread_c $(XDAT) >t_syspread_c.csv
 	./t_copy_c >t_copy_c.csv

plotit.py

@@ -27,16 +27,16 @@ copy_go  = loadxy("t_copy_go.csv")
 
 
 plt.title("Timing for syspread & memcopy")
-plotxy(pread_c,  label="syspread/c")
-plotxy(pread_go, label="syspread/go")
+#plotxy(pread_c,  label="syspread/c")
+#plotxy(pread_go, label="syspread/go")
 plotxy(copy_c,   label="copy/c")
 plotxy(copy_go,  label="copy/go")
 
-assert pread_c[0] == copy_c[0]
-plotxy((pread_c[0], np.array(pread_c[1]) - np.array(copy_c[1])), label="syspread/c - copy/c")
+#assert pread_c[0] == copy_c[0]
+#plotxy((pread_c[0], np.array(pread_c[1]) - np.array(copy_c[1])), label="syspread/c - copy/c")
 
 plt.legend()
 plt.ylabel('time (ns)')
 plt.xlabel('buffer size (bytes)')
-#plt.show()
-plt.savefig('syspread.png')
+plt.show()
+#plt.savefig('syspread.png')

t_copy_c.c

@@ -22,9 +22,9 @@ double microtime() {
 }
 
 //		 12345678
-#define	NITER	1000000
+#define	NITER	100000
 
-#define	BUFSIZE	4096
+#define	BUFSIZE	64*1024
 static char buf[BUFSIZE];
 static char buf2[BUFSIZE];
 
@@ -48,12 +48,12 @@ int main() {
 		printf("%ld\t%.1f\n", size, (Tend - Tstart) / NITER / 1E-9);
 
 
-		if (size < 16) {
-			size += 1;	// detailed start
-		} else if  (size < 128) {
-			size += 16;
+		if (size < 1024) {
+			size += 128;	// detailed start
+		} else if  (size < 8*1024) {
+			size += 256;
 		} else {
-			size += 128;
+			size += 512;
 		}
 	}
 }

t_copy_c.csv

-0	2.8
-1	2.4
-2	2.7
-3	2.7
-4	3.0
-5	2.9
-6	3.0
-7	3.0
-8	2.4
-9	2.5
-10	2.5
-11	2.5
-12	2.6
-13	2.6
-14	2.5
-15	2.5
-16	2.4
-32	2.5
-48	2.5
-64	2.1
-80	4.3
-96	2.7
-112	3.5
-128	4.6
-256	3.5
-384	5.3
-512	6.8
-640	7.6
-768	8.7
-896	10.0
-1024	11.2
-1152	12.1
-1280	13.0
-1408	14.2
-1536	15.4
-1664	16.7
-1792	17.8
-1920	18.9
-2048	20.1
-2176	22.4
-2304	24.2
-2432	25.8
-2560	26.6
-2688	27.6
-2816	28.4
-2944	29.6
-3072	30.9
-3200	32.1
-3328	33.4
-3456	34.4
-3584	35.9
-3712	36.6
-3840	38.1
-3968	38.9
-4096	41.0
+0	3.2
+128	5.6
+256	4.2
+384	6.4
+512	8.3
+640	9.3
+768	10.5
+896	12.1
+1024	13.6
+1280	15.7
+1536	18.6
+1792	21.5
+2048	24.4
+2304	30.1
+2560	32.4
+2816	34.3
+3072	32.7
+3328	35.5
+3584	37.8
+3840	40.4
+4096	43.4
+4352	56.7
+4608	58.7
+4864	58.4
+5120	61.1
+5376	63.1
+5632	65.2
+5888	67.5
+6144	69.9
+6400	72.3
+6656	75.0
+6912	77.0
+7168	79.3
+7424	82.1
+7680	84.1
+7936	86.4
+8192	88.8
+8704	93.8
+9216	98.2
+9728	102.9
+10240	107.7
+10752	114.0
+11264	117.1
+11776	121.8
+12288	126.5
+12800	131.2
+13312	135.9
+13824	140.7
+14336	145.9
+14848	150.1
+15360	154.8
+15872	159.9
+16384	164.6
+16896	169.5
+17408	173.7
+17920	180.2
+18432	191.6
+18944	207.3
+19456	208.8
+19968	228.3
+20480	231.0
+20992	250.4
+21504	273.9
+22016	285.3
+22528	283.4
+23040	314.9
+23552	326.2
+24064	343.7
+24576	366.6
+25088	365.5
+25600	349.5
+26112	360.2
+26624	369.0
+27136	382.2
+27648	391.7
+28160	398.4
+28672	404.0
+29184	403.7
+29696	417.0
+30208	424.5
+30720	433.0
+31232	443.6
+31744	454.6
+32256	466.0
+32768	470.1
+33280	477.0
+33792	502.5
+34304	507.4
+34816	512.7
+35328	526.8
+35840	531.2
+36352	524.9
+36864	538.7
+37376	546.9
+37888	558.5
+38400	547.9
+38912	560.2
+39424	578.5
+39936	585.7
+40448	593.4
+40960	597.1
+41472	604.7
+41984	598.6
+42496	604.1
+43008	622.3
+43520	664.6
+44032	661.4
+44544	665.8
+45056	666.3
+45568	669.8
+46080	678.6
+46592	687.2
+47104	691.2
+47616	702.5
+48128	711.8
+48640	720.3
+49152	723.1
+49664	725.4
+50176	733.2
+50688	759.3
+51200	771.2
+51712	788.2
+52224	811.3
+52736	833.7
+53248	819.3
+53760	810.9
+54272	818.0
+54784	815.6
+55296	825.8
+55808	824.0
+56320	831.1
+56832	851.1
+57344	863.8
+57856	865.2
+58368	865.8
+58880	876.5
+59392	887.2
+59904	905.3
+60416	920.3
+60928	927.7
+61440	925.2
+61952	925.3
+62464	954.2
+62976	990.2
+63488	1002.5
+64000	1049.7
+64512	1100.6
+65024	1079.8
+65536	1041.3

t_copy_go.csv

-0	2.0
-1	3.8
-2	3.1
-3	3.2
-4	2.4
-5	3.5
-6	3.5
-7	3.5
-8	2.4
-9	3.5
-10	3.5
-11	3.5
-12	3.5
-13	3.5
-14	3.4
-15	3.4
-16	2.9
-32	3.0
-48	4.5
-64	4.0
-80	6.6
-96	6.6
-112	7.1
-128	6.9
-256	10.4
-384	10.8
+0	2.6
+128	5.7
+256	8.7
+384	10.5
 512	12.2
-640	13.2
-768	14.5
-896	15.7
-1024	16.8
-1152	18.3
-1280	19.3
-1408	20.5
-1536	21.4
-1664	22.8
-1792	24.1
-1920	25.1
-2048	26.0
-2176	27.5
-2304	28.9
-2432	29.6
-2560	31.3
-2688	32.7
-2816	33.5
-2944	34.6
-3072	35.5
-3200	37.0
-3328	38.2
-3456	39.2
-3584	40.8
-3712	41.8
-3840	43.0
-3968	44.0
-4096	45.3
+640	13.5
+768	14.4
+896	15.2
+1024	16.3
+1280	18.7
+1536	20.6
+1792	23.9
+2048	25.4
+2304	28.3
+2560	30.8
+2816	33.4
+3072	35.2
+3328	37.5
+3584	39.5
+3840	41.9
+4096	44.6
+4352	47.2
+4608	49.4
+4864	51.4
+5120	54.1
+5376	56.1
+5632	58.8
+5888	61.3
+6144	63.3
+6400	66.3
+6656	68.2
+6912	70.3
+7168	73.6
+7424	75.4
+7680	78.4
+7936	79.8
+8192	82.5
+8704	87.1
+9216	91.8
+9728	96.9
+10240	101.7
+10752	106.0
+11264	112.3
+11776	116.2
+12288	121.1
+12800	125.9
+13312	130.3
+13824	134.4
+14336	141.7
+14848	148.7
+15360	149.0
+15872	155.1
+16384	172.2
+16896	172.4
+17408	179.1
+17920	228.3
+18432	329.6
+18944	389.0
+19456	417.7
+19968	433.6
+20480	449.5
+20992	469.1
+21504	477.9
+22016	479.2
+22528	516.0
+23040	535.3
+23552	530.1
+24064	533.7
+24576	532.2
+25088	512.2
+25600	513.4
+26112	502.6
+26624	550.6
+27136	539.4
+27648	561.1
+28160	620.1
+28672	550.4
+29184	557.4
+29696	554.1
+30208	547.6
+30720	588.3
+31232	617.6
+31744	607.4
+32256	599.0
+32768	648.5
+33280	643.8
+33792	617.3
+34304	595.0
+34816	666.0
+35328	700.9
+35840	656.9
+36352	714.3
+36864	699.3
+37376	655.7
+37888	704.7
+38400	672.1
+38912	658.8
+39424	699.6
+39936	753.4
+40448	783.6
+40960	754.5
+41472	778.1
+41984	749.7
+42496	761.4
+43008	772.0
+43520	854.6
+44032	830.6
+44544	819.5
+45056	860.8
+45568	844.8
+46080	816.9
+46592	853.8
+47104	883.0
+47616	890.1
+48128	849.4
+48640	895.0
+49152	913.8
+49664	946.5
+50176	898.4
+50688	880.0
+51200	888.6
+51712	910.5
+52224	954.9
+52736	1005.7
+53248	976.1
+53760	985.0
+54272	961.7
+54784	977.5
+55296	986.8
+55808	1006.3
+56320	1021.0
+56832	1021.5
+57344	1042.4
+57856	1112.4
+58368	1054.4
+58880	990.8
+59392	1078.0
+59904	1139.9
+60416	1123.0
+60928	1072.5
+61440	994.6
+61952	1100.5
+62464	1157.0
+62976	1097.9
+63488	1138.8
+64000	1188.8
+64512	1226.6
+65024	1214.5
+65536	1150.0

t_copy_go.go

@@ -6,9 +6,9 @@ import (
 )
 
 //             12345678
-const Niter = 1000000
+const Niter = 100000
 
-const BufSize = 4096
+const BufSize = 64*1024
 var buf  [BufSize]byte
 var buf2 [BufSize]byte
 
@@ -31,12 +31,12 @@ func main() {
 		fmt.Printf("%v\t%.1f\n", size, float64(Tend.Sub(Tstart).Nanoseconds()) / Niter)
 
 		switch {
-		case size < 16:
-			size += 1	// detailed start
-		case size < 128:
-			size += 16
+		case size < 1024:
+			size += 128	// detailed start
+		case size < 8*1024:
+			size += 256
 		default:
-			size += 128
+			size += 512
 		}
 	}
 }