Bug ID: 6347493 tar of 25K empty directory entries in ZFS takes 30+ seconds of system time on 2GHz amd64

Bug ID	6347493
Synopsis	tar of 25K empty directory entries in ZFS takes 30+ seconds of system time on 2GHz amd64
State	10-Fix Delivered (Fix available in build)
Category:Subcategory	kernel:zfs
Keywords	onnv_triage
Responsible Engineer	Matthew Ahrens
Reported Against	snv_27
Duplicate Of
Introduced In
Commit to Fix	snv_28
Fixed In	snv_28
Release Fixed	solaris_nevada(snv_28)
Related Bugs	6347448 , 6349502
Submit Date	8-November-2005
Last Update Date	3-December-2005
Description	In an empty ZFS directory: bash-3.00$ ls bash-3.00$ mkdir bench bash-3.00$ cd bench bash-3.00$ /bin/time mkdir `cat /usr/dict/words` real 0.7 user 0.0 sys 0.7 bash-3.00$ /bin/time tar cf /tmp/bench.tar . real 30.4 user 0.4 sys 29.9 bash-3.00$ truss -c tar cf /tmp/bench.tar . syscall seconds calls errors _exit .000 1 write .040 1258 open .000 4 1 close .444 75436 unlink .000 1 1 chdir 1.110 50289 brk .000 8 getpid .000 2 sysi86 .000 1 execve .000 1 fcntl .254 50288 fstatat64 .449 25144 openat .381 50287 sigaction .000 6 getcontext .000 1 setustack .000 1 mmap .000 15 munmap .000 4 xstat .000 4 getrlimit .000 1 memcntl .000 3 sysconfig .000 2 lwp_private .000 1 llseek .389 75429 door_info .000 2 door_call .000 2 resolvepath .000 5 getdents64 30.314 75430 stat64 .674 25143 fstat64 .303 50288 open64 .186 25146 getcwd .000 2 -------- ------ ---- sys totals: 34.549 504205 2 usr time: .954 elapsed: 52.490 getdents64 is clearly the problem.
Work Around	N/A
Comments	N/A

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