From d2160d053838e36df83e5fe3a9ca20abad588a4c Mon Sep 17 00:00:00 2001 From: Olaf Faaland Date: Mon, 26 Feb 2018 20:32:49 -0500 Subject: Record skipped MMP writes in multihost_history Once per pass through the MMP thread's loop, the vdev tree is walked to find a suitable leaf to write the next MMP block to. If no such leaf is found, the thread sleeps for a while and resumes at the top of the loop. Add an entry to multihost_history when no leaf can be found, and record the reason in the error column. The error code for such entries is a bitfield, displayed in hex: 0x1 At least one vdev (interior or leaf) was not writeable. 0x2 At least one writeable leaf vdev was found, but it had a pending MMP write. timestamp = the time in seconds since the epoch when no leaf could be found originally. duration = the time (in ns) during which no MMP block was written for this reason. This does not include the preceeding inter-write period nor the following inter-write period. vdev_guid = the number of sequential cycles of the MMP thread looop when this occurred. Sample output, truncated to fit: For records of skipped MMP writes the right-most column, vdev_path, is reported as "-". id txg timestamp error duration mmp_delay vdev_guid ... 936 11 1520036441 0 146264 891422313 1740883117838 ... 937 11 1520036441 0 163956 888356657 7320395061548 ... 938 11 1520036442 0 130690 885314969 7320395061548 ... 939 11 1520036442 0 2001068577 882296582 1740883117838 ... 940 11 1520036443 0 161806 882296582 7320395061548 ... 941 11 1520036443 0x2 0 998020546 1 ... 942 11 1520036444 0 136585 998020546 7320395061548 ... 943 11 1520036444 0x2 0 998020257 1 ... 944 11 1520036445 5 2002662964 994160219 1740883117838 ... 945 11 1520036445 0x2 998073118 994160219 3 ... 946 11 1520036447 0 247136 994160219 7320395061548 ... Reviewed-by: Brian Behlendorf Signed-off-by: Olaf Faaland Closes #7212 --- include/sys/mmp.h | 1 + include/sys/spa.h | 6 ++++-- 2 files changed, 5 insertions(+), 2 deletions(-) (limited to 'include/sys') diff --git a/include/sys/mmp.h b/include/sys/mmp.h index 1ce685f9c..c99c124e6 100644 --- a/include/sys/mmp.h +++ b/include/sys/mmp.h @@ -43,6 +43,7 @@ typedef struct mmp_thread { uberblock_t mmp_ub; /* last ub written by sync */ zio_t *mmp_zio_root; /* root of mmp write zios */ uint64_t mmp_kstat_id; /* unique id for next MMP write kstat */ + int mmp_skip_error; /* reason for last skipped write */ } mmp_thread_t; diff --git a/include/sys/spa.h b/include/sys/spa.h index 7b529330f..62832eff0 100644 --- a/include/sys/spa.h +++ b/include/sys/spa.h @@ -887,10 +887,12 @@ extern txg_stat_t *spa_txg_history_init_io(spa_t *, uint64_t, struct dsl_pool *); extern void spa_txg_history_fini_io(spa_t *, txg_stat_t *); extern void spa_tx_assign_add_nsecs(spa_t *spa, uint64_t nsecs); +extern int spa_mmp_history_set_skip(spa_t *spa, uint64_t mmp_kstat_id); extern int spa_mmp_history_set(spa_t *spa, uint64_t mmp_kstat_id, int io_error, hrtime_t duration); -extern void spa_mmp_history_add(uint64_t txg, uint64_t timestamp, - uint64_t mmp_delay, vdev_t *vd, int label, uint64_t mmp_kstat_id); +extern void *spa_mmp_history_add(spa_t *spa, uint64_t txg, uint64_t timestamp, + uint64_t mmp_delay, vdev_t *vd, int label, uint64_t mmp_kstat_id, + int error); /* Pool configuration locks */ extern int spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw); -- cgit v1.2.3