Date: Thu, 20 Mar 2008 20:02:54 -0700 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: freebsd-current@freebsd.org Subject: Extremely slooooow __sys_ftruncate? Message-ID: <20080321030254.GA98444@troutmask.apl.washington.edu>
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In the process of helping to debug a problem with gcc-4.4.0 (actually a gfortran problem), I run gprof on the executable. The profile shows that __sys_ftruncate is extremely slow. % cumulative self self total time seconds seconds calls ms/call ms/call name 85.6 6.05 6.05 51830 0.12 0.12 __sys_ftruncate [2] 5.6 6.44 0.40 0 100.00% .mcount (101) 1.7 6.56 0.12 51872 0.00 0.00 _lseek [5] 1.6 6.67 0.11 52055 0.00 0.00 sigprocmask [6] 0.8 6.73 0.06 103687 0.00 0.00 memset [14] 0.4 6.76 0.03 488 0.06 0.06 __sys_write [18] 0.4 6.79 0.03 0 100.00% formatted_transfer_scalar time ./z 184.21 real 0.98 user 6.57 sys This program should finish well under 184 seconds. The same program and exact same gcc/gfortran source on linux shows real 0m0.555s user 0m0.103s sys 0m0.452s Is __sys_ftruncate known to have performance problems? -- Steve
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