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 splitblock 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 splitblock. 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 splitblock-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 splitblock-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) v1->v2: use splitblock instead of block add restriction (align to the page size) to splitblock size adjust the position of prepare_splitblock_table and check the return code use --splitblock-size to specify splitblock size and modify the print_info.c Zhou Wenjian (5): Add support for splitblock Add tools for reading and writing from splitblock table Add module of generating table Add module of calculating start_pfn and end_pfn in each dumpfile Add support for --splitblock-size makedumpfile.8 | 16 ++++ makedumpfile.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- makedumpfile.h | 17 ++++ print_info.c | 16 ++++- 4 files changed, 296 insertions(+), 7 deletions(-)
