On 03/16/2014 09:32 PM, Chen Gang wrote: > On 03/08/2014 09:58 PM, Chen Gang wrote: >> OK, thanks. >> >> Next, I will/should continue to analyse the performance issue for 9pfs >> when users drop into a long directory path under bash shell. >> > > After have a test, I am sure it is not 9pfs issue, either not Qemu's > issue, it's Linux kernel vfs or block sub-systems' issue. The related > test environments (originally, our 9pfs is upper on ext4): > > - for ext4 file system under my Fedora laptop (Qemu does not start). > > - for ntfs file system under my Fedora laptop (Qemu does not start). > > - for ext4 file system under my Ubuntu in Qemu. > > For a very long file name (e.g. > 3K long), all of them are very very > slow. (and I also tested the ext2 /boot partition under Ubuntu in Qemu, > it is not slow, I guess the reson is its partition size is small). > > > Next, I will/shall communicate with upstream kernel for it. :-) > > >> Although I am not quite sure, hope I can find the root cause within >> month (2014-03-31). >> >> Welcome any suggestions, discussions, and completions for it. >> >> Thanks. >> > >
Sorry, after give a little more test, for the lower performance issue under a long deep path, 'bash' is the direct cause (may also be root cause). Also sorry, 'bash' is out of my focusing border now, so I provide the related information below, welcome any members (e.g. 'bash', fedora, or ubuntu members) to help check, when they have time, thanks. Environments (e.g. fedora 17): [root@gchen ~]# uname -a Linux gchen 3.14.0-rc7-next-20140321 #2 SMP Sun Mar 23 19:46:37 CST 2014 x86_64 x86_64 x86_64 GNU/Linux [root@gchen ~]# cat /etc/*-release Fedora release 17 (Beefy Miracle) NAME=Fedora VERSION="17 (Beefy Miracle)" ID=fedora VERSION_ID=17 PRETTY_NAME="Fedora 17 (Beefy Miracle)" ANSI_COLOR="0;34" CPE_NAME="cpe:/o:fedoraproject:fedora:17" Fedora release 17 (Beefy Miracle) Fedora release 17 (Beefy Miracle) 'bash' is very busy under user mode (I am only one cpu): top - 20:12:01 up 23 min, 5 users, load average: 0.60, 0.35, 0.33 Tasks: 137 total, 2 running, 135 sleeping, 0 stopped, 0 zombie Cpu(s): 97.1%us, 2.9%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1942468k total, 820896k used, 1121572k free, 40060k buffers Swap: 0k total, 0k used, 0k free, 446328k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 4010 root 20 0 113m 5236 3096 R 92.3 0.3 3:57.19 -bash 2955 root 20 0 136m 21m 10m S 2.9 1.1 0:16.00 /usr/bin/Xorg :0 -background none -logverbose 7 -auth /var/run/gdm/auth-for-gdm-8 3860 gchen 20 0 582m 28m 19m S 1.9 1.5 0:22.93 gnome-terminal 3348 gchen 20 0 1405m 117m 46m S 1.0 6.2 0:23.34 /usr/bin/gnome-shell 3728 gchen 20 0 442m 8248 6140 S 1.0 0.4 0:12.05 /usr/bin/ibus-daemon -r --xim ... The related 'bash' stack is below (each time, always drop into it): #0 0x00000036bb290c1c in strcoll_l () from /lib64/libc.so.6 #1 0x000000000047ff48 in ?? () #2 0x0000000000480517 in ?? () #3 0x0000000000480fb7 in ?? () #4 0x00000000004806e0 in ?? () #5 0x0000000000480fb7 in ?? () #6 0x00000000004806e0 in ?? () #7 0x0000000000482528 in xstrmatch () #8 0x0000000000456f79 in binary_test () #9 0x000000000042f308 in ?? () #10 0x000000000042f449 in ?? () #11 0x0000000000432379 in execute_command_internal () #12 0x000000000043583e in execute_command () #13 0x000000000043295e in execute_command_internal () #14 0x000000000043349f in execute_command_internal () #15 0x000000000043583e in execute_command () #16 0x0000000000433464 in execute_command_internal () #17 0x000000000043583e in execute_command () #18 0x0000000000433464 in execute_command_internal () #19 0x000000000043583e in execute_command () #20 0x0000000000433464 in execute_command_internal () #21 0x000000000043583e in execute_command () #22 0x0000000000433464 in execute_command_internal () #23 0x000000000043583e in execute_command () #24 0x0000000000433464 in execute_command_internal () #25 0x000000000043583e in execute_command () #26 0x0000000000433464 in execute_command_internal () #27 0x0000000000432613 in execute_command_internal () #28 0x000000000043440e in ?? () #29 0x0000000000431a8c in ?? () #30 0x0000000000432873 in execute_command_internal () #31 0x000000000043583e in execute_command () #32 0x000000000043310d in execute_command_internal () #33 0x000000000043349f in execute_command_internal () #34 0x000000000043583e in execute_command () #35 0x0000000000433464 in execute_command_internal () #36 0x000000000043583e in execute_command () #37 0x0000000000433464 in execute_command_internal () #38 0x000000000043583e in execute_command () #39 0x0000000000433464 in execute_command_internal () #40 0x000000000043583e in execute_command () #41 0x0000000000433464 in execute_command_internal () #42 0x000000000043583e in execute_command () #43 0x0000000000433464 in execute_command_internal () #44 0x000000000043583e in execute_command () #45 0x0000000000433464 in execute_command_internal () #46 0x000000000043583e in execute_command () #47 0x0000000000433464 in execute_command_internal () #48 0x000000000043583e in execute_command () #49 0x0000000000433464 in execute_command_internal () #50 0x000000000043583e in execute_command () #51 0x0000000000433464 in execute_command_internal () #52 0x0000000000432613 in execute_command_internal () #53 0x000000000043440e in ?? () #54 0x00000000004346b5 in execute_shell_function () #55 0x00000000004693c7 in gen_compspec_completions () #56 0x0000000000469b69 in ?? () #57 0x0000000000469cac in programmable_completions () #58 0x0000000000463d01 in ?? () #59 0x000000000049130f in ?? () #60 0x0000000000491d68 in rl_complete_internal () #61 0x000000000048978d in _rl_dispatch_subseq () #62 0x0000000000489cf8 in readline_internal_char () #63 0x000000000048a1a5 in readline () #64 0x000000000041e59c in ?? () #65 0x0000000000420158 in ?? () #66 0x0000000000422d76 in ?? () #67 0x000000000042610b in yyparse () #68 0x000000000041de6a in parse_command () #69 0x000000000041df36 in read_command () #70 0x000000000041e193 in reader_loop () #71 0x000000000041c6e5 in main () Thanks. -- Chen Gang Open, share and attitude like air, water and life which God blessed