What is lstat64 process in LSWS?

Bono

Well-Known Member
#1
Can someone check my stats. It looks like lstat64 is taking ~40% of resources and generates 20K of errors.

Thanks

Code:
Process 15067 attached - interrupt to quit
Process 15067 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 38.84    0.025425           0    781068     20395 lstat64
 23.23    0.015208           1     24887           read
  6.63    0.004340         620         7           clone
  6.10    0.003996           7       604           select
  5.53    0.003620           0     15141           write
  4.67    0.003057         437         7           waitpid
  2.40    0.001569           8       193           munmap
  2.25    0.001472           0     11441        98 open
  2.19    0.001433           0     32672           fcntl64
  1.65    0.001082           2       538         1 writev
  1.36    0.000892           0     28704           time
  1.36    0.000891           0     20771      7775 access
  1.32    0.000867           0     18282       300 stat64
  0.76    0.000498           0     13974           poll
  0.45    0.000293           0      9377      8744 readlink
  0.42    0.000276           0     11678           close
  0.16    0.000105           0       314           connect
  0.13    0.000087           0     11830           fstat64
  0.09    0.000061           0      1998           getcwd
  0.09    0.000060           3        24           getdents
  0.07    0.000045           0      2911           lseek
  0.04    0.000028           0       649           chdir
  0.04    0.000028           0      1804           flock
  0.04    0.000027           0      1047           gettimeofday
  0.04    0.000027           0       314           socket
  0.03    0.000020           0      1220           rt_sigaction
  0.02    0.000016           0       305           shutdown
  0.02    0.000012           0       610           rt_sigprocmask
  0.01    0.000006           0        49           brk
  0.01    0.000006           0       915           setitimer
  0.01    0.000006           0       180           _llseek
  0.01    0.000006           0      1220       305 setsockopt
  0.00    0.000000           0         1           chmod
  0.00    0.000000           0         7           pipe
  0.00    0.000000           0         9           ioctl
  0.00    0.000000           0       298           getppid
  0.00    0.000000           0         1           nanosleep
  0.00    0.000000           0         4           pwrite64
  0.00    0.000000           0       191           mmap2
  0.00    0.000000           0         1           getuid32
  0.00    0.000000           0         1           getgroups32
  0.00    0.000000           0         2         1 chown32
  0.00    0.000000           0         1           accept
  0.00    0.000000           0         9           send
  0.00    0.000000           0         9           recvfrom
------ ----------- ----------- --------- --------- ----------------
100.00    0.065459                995268     37619 total
Code:
Process 15695 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 51.37    0.024161           0    717256     17900 lstat64
 18.25    0.008585           0     21235           read
  6.85    0.003223         403         8           clone
  4.25    0.001998           3       660           select
  2.57    0.001209           0     12744           write
  2.45    0.001151           0     10116           open
  2.22    0.001043           3       338           munmap
  2.05    0.000963           0     11757           poll
  1.75    0.000823           0     15454       380 stat64
  1.57    0.000740           0     19625      6607 access
  1.17    0.000552           0     10480           close
  1.01    0.000474           0      7748      7748 readlink
  0.85    0.000402           0     25883           fcntl64
  0.82    0.000384           0     22707           time
  0.81    0.000383         192         2           brk
  0.68    0.000320           1       341        24 connect
  0.28    0.000131           0       513           chdir
  0.23    0.000108           0     10658           fstat64
  0.17    0.000079          10         8           waitpid
  0.11    0.000053           0      1481           getcwd
  0.11    0.000052           0       336           mmap2
  0.10    0.000049           0       464           writev
  0.09    0.000041           0      3464           lseek
  0.05    0.000025           0       144           send
  0.04    0.000020           0       979           gettimeofday
  0.04    0.000020           0      2036           flock
  0.04    0.000017           0       735           setitimer
  0.04    0.000017           0       980       245 setsockopt
  0.02    0.000008           0       980           rt_sigaction
  0.01    0.000006           0        72           ioctl
  0.00    0.000000           0         8           pipe
  0.00    0.000000           0       415           getppid
  0.00    0.000000           0       280           _llseek
  0.00    0.000000           0        12           getdents
  0.00    0.000000           0         1           nanosleep
  0.00    0.000000           0       490           rt_sigprocmask
  0.00    0.000000           0       342           socket
  0.00    0.000000           0        48           recv
  0.00    0.000000           0        72           recvfrom
  0.00    0.000000           0       245           shutdown
  0.00    0.000000           0        24           getsockopt
------ ----------- ----------- --------- --------- ----------------
100.00    0.047037                901141     32904 total
Code:
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 47.83    0.034325           0   1210443     32180 lstat64
 21.35    0.015324           0     32440           read
  6.99    0.005014           0     21193           write
  5.57    0.003996           6       692           select
  2.17    0.001558           0     17956       432 open
  2.15    0.001546         193         8           clone
  1.91    0.001370           0     27390       704 stat64
  1.71    0.001226           0     31332     11251 access
  1.67    0.001198           3       372           munmap
  1.37    0.000982           0      2787           getcwd
  1.37    0.000980           0     19558           poll
  1.32    0.000945           0     44925           fcntl64
  1.16    0.000830           0     13669     13669 readlink
  0.92    0.000660           1       519           brk
  0.59    0.000425           0     42474           time
  0.51    0.000369           0     17954           close
  0.46    0.000327           0       725           writev
  0.24    0.000174           0     18341           fstat64
  0.19    0.000134           0       408           connect
  0.15    0.000105           0      5357           lseek
  0.10    0.000071           9         8           waitpid
  0.06    0.000041           0      2970           flock
  0.05    0.000036           0       408           socket
  0.04    0.000031           0       826           chdir
  0.04    0.000026           0      1596       399 setsockopt
  0.03    0.000023           0      1517           gettimeofday
  0.03    0.000021           0      1600           rt_sigaction
  0.02    0.000011           0       370           mmap2
  0.01    0.000007           0       399           shutdown
  0.01    0.000006           0       343           _llseek
  0.01    0.000005           0       802           rt_sigprocmask
  0.00    0.000000           0         8           pipe
  0.00    0.000000           0         9           ioctl
  0.00    0.000000           0       291           getppid
  0.00    0.000000           0      1203           setitimer
  0.00    0.000000           0        54           getdents
  0.00    0.000000           0         2           nanosleep
  0.00    0.000000           0        18           pwrite64
  0.00    0.000000           0         9           send
  0.00    0.000000           0         9           recvfrom
------ ----------- ----------- --------- --------- ----------------
100.00    0.071766               1520985     58635 total
And here is my vmstat:

Code:
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  0 134432 160172 309076 2387020    0    0    10    12    0    0 14  4 80  1  0
 2  0 134432 162280 309084 2387244    0    0     0   768 1250 2993 19  4 77  1  0
 0  0 134432 159876 309112 2387512    0    0    12   449 1306 3328 47  8 44  1  0
 4  0 134432 160056 309152 2387468    0    0    76   160 1402 3282 27  5 68  1  0
 1  0 134432 162660 309164 2388340    0    0     0  1125 1416 3002 46  7 43  3  0
 4  0 134432 162908 309204 2388364    0    0     0   319 1286 3130 51  9 39  1  0
 1  0 134432 163032 309212 2388280    0    0     0   161 1197 3359 30  6 64  0  0
 2  0 134432 160924 309256 2388708    0    0     0   601 1210 3096 46  8 45  1  0
 1  0 134432 158644 309316 2389056    0    0     7   475 1448 3337 25  3 70  1  0
 2  0 134432 158692 309332 2389140    0    0     0   241 1270 3589 21  6 73  0  0
 1  0 134432 159916 309384 2389236    0    0     3   325 1351 3463 20  4 75  1  0
 4  0 134432 162632 309416 2389252    0    0    19   217 1299 3286 16  3 80  1  0
 2  0 134432 163004 309476 2389360    0    0     0   191 1173 2801 17  5 77  1  0
 
Last edited:

NiteWave

Administrator
#2
lstat64() -- Get File or Link Information (Large File Enabled)

It looks like lstat64 is taking ~40% of resources and generates 20K of errors.
check your error/access log, there maybe many "File Not Found" entries.

The strace result tells how many resource wasted for file/directory/link not found errors.

Fix "file not found" errors of your web pages, see if any difference.
 
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