Thanks steve and andrew. I have tried following two methods:(1) use mdb to set mblk_pull_len to 0. The xcall is still very high and same to before doing that. (2) set tcp_max_buf to 65536 for control size of send and receive buffer, the xcall and kernel utilization is reduced very much and "mpstat -a 2" has following output:
SET minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl sze 0 76 0 17386 19029 876 1329 99 130 298 2 1719 0 1 0 99 16 SET minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl sze 0 8152 0 725 161524 119596 650416 43958 40670 65765 3 356206 7 52 0 41 16 SET minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl sze 0 6460 0 804 163550 121536 663085 44498 42610 66349 15 352296 6 53 0 40 16 SET minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl sze 0 7560 0 711 168416 123996 667632 46738 46100 67780 13 374021 7 53 0 40 16 2009/7/10 Andrew Gallatin <galla...@cs.duke.edu> > Steve Sistare wrote: > >> This has the same signature as CR: >> >> 6694625 Performance falls off the cliff with large IO sizes >> http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6694625 >> >> which was raised in the network forum thread "expensive pullupmsg in >> kstrgetmsg()" >> >> http://www.opensolaris.org/jive/thread.jspa?messageID=229124𷼄 >> >> This was fixed in nv_112, so it just missed OpenSolaris 2009.06. >> >> The discussion says that the issue gets worse when the RX socket >> buffer size is increased, so you could try reducing it as a workaround. >> > > I'm the one who filed that bug.. > > You can tell if its this particular bug by using mdb to > set mblk_pull_len to 0 and seeing if that reduces the > xcalls due to dblk_lastfree_oversize > > Cheers, > > Drew >
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