On unpatched systems, txg_quiesce gets inlined and is hidden from dtrace. The zilstat script (http://www.richardelling.com/Home/scripts-and-programs-1/zilstat) will report that no probes could be found for fbt::txg_quiesce:entry After patching zilstat will report lines like these: N-Bytes N-Bytes/s N-Max-Rate B-Bytes B-Bytes/s B-Max-Rate ops <=4kB 4-32kB >=32kB 0 0 0 0 0 0 0 0 0 0 504 504 504 131072 131072 131072 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Fix: In sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c, prefix the txg_quiesce function with __attribute__ ((noinline)) Patch attached with submission follows: How-To-Repeat: run zilstat on an unpatched system, it will report the missing probe for fbt::txg_quiesce:entry and exits
This is also applicable to FreeBSD 10.0-PRERELEASE r260387M Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c =================================================================== --- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c (revision 260387) +++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c (working copy) @@ -354,7 +354,7 @@ * On return, the transaction group has reached a stable state in which it can * then be passed off to the syncing context. */ -static void +static __attribute__ ((noinline)) void txg_quiesce(dsl_pool_t *dp, uint64_t txg) { tx_state_t *tx = &dp->dp_tx;
Responsible Changed From-To: freebsd-bugs->freebsd-fs Over to maintainer(s).
This is also missing on FreeBSD 10.1-RELEASE-p5, keeping the same zilstat script from working.
Fixed by: https://svnweb.freebsd.org/changeset/base/278040