Hello I see some mismatches between the summary produced by blkparse and btt. Please help me find out what this means. (Please CC me because I am not a member of this list) blkparse and btt output is given at the end of this mail. blkparse says 9421 IOs queued and 2948 completed. btt Q2C number is 5880 which does not match either one of the above. What does this Q2C number refer to and why does it not match with blkparse output. After some research with btt source code, I found that btt does not take all the “Q”s in account. I think this causes the difference. For example, below there are 3 Qs, but btt skips the later 2 Qs. It seems it does so because the offset is the same. What is the thinking behind this? >From blkparse output ----- 8,16 5 1786 1.463926383 11710 Q WS 0 + 64 [fio] 8,16 5 1787 1.463930850 11710 G WS 0 + 64 [fio] 8,16 5 1788 1.463932084 11710 P N [fio] 8,16 5 1789 1.463934486 11710 I WS 0 + 64 [fio] 8,16 5 1790 1.463935589 11710 U N [fio] 1 8,16 5 1791 1.463936993 11710 D WS 0 + 64 [fio] 8,16 3 1 1.463976179 11713 Q WS 0 + 64 [fio] 8,16 3 2 1.463977977 11713 G WS 0 + 64 [fio] 8,16 3 3 1.463978581 11713 P N [fio] 8,16 3 4 1.463979938 11713 I WS 0 + 64 [fio] 8,16 3 5 1.463980277 11713 U N [fio] 1 8,16 3 6 1.463980960 11713 D WS 0 + 64 [fio] 8,16 5 1792 1.464070530 11709 Q WS 0 + 64 [fio] 8,16 5 1793 1.464071714 11709 G WS 0 + 64 [fio] 8,16 5 1794 1.464072083 11709 P N [fio] 8,16 5 1795 1.464074361 11709 I WS 0 + 64 [fio] 8,16 5 1796 1.464074763 11709 U N [fio] 1 8,16 5 1797 1.464075571 11709 D WS 0 + 64 [fio] ----- >From blkparse summary ----- Total (sdb): Reads Queued: 0, 0KiB Writes Queued: 9421, 301472KiB Read Dispatches: 0, 0KiB Write Dispatches: 12955, 301472KiB Reads Requeued: 0 Writes Requeued: 10007 Reads Completed: 0, 0KiB Writes Completed: 2948, 301472KiB Read Merges: 0, 0KiB Write Merges: 5617, 179744KiB PC Reads Queued: 0, 0KiB PC Writes Queued: 0, 0KiB PC Read Disp.: 1583, 0KiB PC Write Disp.: 0, 0KiB PC Reads Req.: 592 PC Writes Req.: 0 PC Reads Compl.: 0 PC Writes Compl.: 0 IO unplugs: 3804 Timer unplugs: 0 ----- >From btt output ----- Q2Q 0.000000001 0.002561115 0.658425073 5879 Q2G 0.000000253 0.319168137 3.810568969 1658 S2G 0.000000450 0.248123138 2.326845231 448 G2I 0.000000056 0.003927394 0.538910707 1894 Q2M 0.000000894 0.141180655 3.745428960 5617 I2D 0.000000258 0.078672901 2.129819436 4857 M2D 0.000000760 0.016032975 0.507792441 6989 D2C 0.000165886 0.006084805 0.149684275 2881 Q2C 0.000675957 0.013519592 4.391495471 5880 ----- Best regards Iram -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
