The issue is discussed at http://lists.infradead.org/pipermail/kexec/2014-March/011289.html This patch implements the idea of 2-pass algorhythm with smaller memory to manage block table. Exactly the algorhythm is still 3-pass,but the time of second pass is much shorter. The tables below show the performence with different size of cyclic-buffer and block. The test is executed on the machine having 128G memory. the value is total time (including first pass and second pass). the value in brackets is the time of second pass. sec cyclic-buffer 1 2 4 8 16 32 64 block-size 1M 4.74(0.00) 4.22(0.01) 3.94(0.01) 3.78(0.02) 3.71(0.03) 3.73(0.07) 3.74(0.10) 2M 4.74(0.00) 4.19(0.00) 3.94(0.01) 3.80(0.03) 3.71(0.03) 3.72(0.07) 3.72(0.09) 4M 4.73(0.00) 4.21(0.01) 3.95(0.01) 3.78(0.02) 3.70(0.02) 3.73(0.08) 3.73(0.10) 8M 4.73(0.00) 4.19(0.00) 3.94(0.01) 3.83(0.02) 3.73(0.03) 3.72(0.07) 3.74(0.10) 16M 4.74(0.01) 4.21(0.00) 3.94(0.01) 3.76(0.01) 3.73(0.03) 3.73(0.08) 3.74(0.10) 32M 4.72(0.00) 4.20(0.02) 3.92(0.01) 3.77(0.02) 3.71(0.02) 3.70(0.06) 3.74(0.10) 64M 4.74(0.01) 4.20(0.00) 3.95(0.01) 3.78(0.02) 3.70(0.02) 3.71(0.07) 3.72(0.09) 128M 4.73(0.01) 4.20(0.00) 3.94(0.01) 3.78(0.02) 3.76(0.03) 3.72(0.08) 3.74(0.09) 256M 4.75(0.02) 4.22(0.02) 3.96(0.03) 3.78(0.02) 3.70(0.03) 3.70(0.07) 3.74(0.11) 512M 4.77(0.04) 4.21(0.03) 3.97(0.04) 3.79(0.03) 3.73(0.04) 3.75(0.09) 3.82(0.13) 1G 4.82(0.09) 4.26(0.07) 4.00(0.08) 3.83(0.07) 3.76(0.08) 3.73(0.08) 3.76(0.12) 2G 8.26(3.54) 7.34(3.14) 6.86(2.93) 6.56(2.80) 6.44(2.76) 6.45(2.79) 6.42(2.80) the performence of 3-pass algorhythm origin 8.25(3.54) 7.26(3.11) 6.80(2.91) 6.52(2.80) 6.39(2.76) 6.40(2.78) 6.45(2.85) sec cyclic-buffer 128 256 512 1024 2048 4096 8192 block-size 1M 3.83(0.21) 3.94(0.33) 4.16(0.54) 4.61(0.99) 7.03(3.41) 8.73(5.11) 8.69(5.08) 2M 3.86(0.21) 3.92(0.32) 4.16(0.54) 4.64(0.98) 7.02(3.41) 8.71(5.09) 8.72(5.09) 4M 3.82(0.21) 3.95(0.32) 4.18(0.55) 4.62(0.99) 7.05(3.44) 8.70(5.09) 8.68(5.07) 8M 3.82(0.21) 3.95(0.33) 4.17(0.54) 4.58(0.97) 7.03(3.41) 8.79(5.16) 8.71(5.09) 16M 3.83(0.21) 3.93(0.31) 4.15(0.54) 4.60(0.98) 7.06(3.43) 8.76(5.13) 8.73(5.10) 32M 3.84(0.22) 3.93(0.32) 4.15(0.54) 4.61(0.98) 7.00(3.40) 8.69(5.08) 8.75(5.13) 64M 3.84(0.21) 3.94(0.33) 4.15(0.54) 4.60(0.98) 7.04(3.42) 8.74(5.10) 8.80(5.16) 128M 3.85(0.22) 3.97(0.33) 4.16(0.54) 4.60(0.98) 7.07(3.44) 8.68(5.07) 8.69(5.07) 256M 3.84(0.21) 3.94(0.33) 4.16(0.55) 4.64(1.00) 7.02(3.41) 8.74(5.11) 8.73(5.11) 512M 3.85(0.24) 3.97(0.34) 4.17(0.56) 4.61(0.99) 7.05(3.44) 8.73(5.11) 8.75(5.13) 1G 3.85(0.22) 3.96(0.35) 4.18(0.56) 4.65(1.00) 7.06(3.44) 8.76(5.12) 8.72(5.11) 2G 6.53(2.91) 6.86(3.25) 7.54(3.92) 8.95(5.31) 10.60(6.97) 14.08(10.47) 14.32(10.60) the performence of 3-pass algorhythm origin 6.64(3.05) 6.81(3.24) 7.51(3.93) 8.86(5.30) 10.51(6.94) 13.92(10.36) 14.11(10.55) Zhou Wenjian (5): Add support for block Add tools for reading and writing from block table Add module of generating table Add module of calculating start_pfn and end_pfn in each dumpfile Add support for --block-size makedumpfile.8 | 16 ++++ makedumpfile.c | 245 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- makedumpfile.h | 15 ++++ 3 files changed, 271 insertions(+), 5 deletions(-)
