Linux
不同使用者的執行時間不同
我正在由另一個受限使用者執行簡單
R的工作。root執行時間明顯不同。問題的根源是什麼？更多的資訊
這是我比較執行時間的方式：
# time /share/binary/R/bin/R CMD BATCH s1n\=50.R real 0m0.278s user 0m0.217s sys 0m0.032s # su john $ time /share/binary/R/bin/R CMD BATCH s1n\=50.R在
john使用者下執行需要很長時間並且永遠不會完成！perf在這些間隔期間的輸出是：PerfTop: 906 irqs/sec kernel:19.3% exact: 0.0% [1000Hz cycles], (all, 8 CPUs) ------------------------------------------------------------------------------------------------------------------------------------------------------------- samples pcnt function DSO _______ _____ _____________________________ _______________________________ 598.00 14.5% __GI_vfprintf /lib64/libc-2.12.so 194.00 4.7% intel_idle [kernel.kallsyms] 176.00 4.3% read_hpet [kernel.kallsyms] 170.00 4.1% bcEval /usr/local/R/lib64/R/bin/exec/R 141.00 3.4% ___printf_fp /lib64/libc-2.12.so 138.00 3.4% __strchrnul /lib64/libc-2.12.so 121.00 2.9% Rf_cons /usr/local/R/lib64/R/bin/exec/R 120.00 2.9% R_gc_internal /usr/local/R/lib64/R/bin/exec/R 91.00 2.2% _IO_default_xsputn_internal /lib64/libc-2.12.so 88.00 2.1% Rf_allocVector /usr/local/R/lib64/R/bin/exec/R 84.00 2.0% _IO_file_xsputn_internal /lib64/libc-2.12.so 82.00 2.0% scientific /usr/local/R/lib64/R/bin/exec/R 72.00 1.7% MatrixSubset /usr/local/R/lib64/R/bin/exec/R 71.00 1.7% duplicate1 /usr/local/R/lib64/R/bin/exec/R 68.00 1.7% floor /lib64/libm-2.12.so 64.00 1.6% __strcmp_sse42 /lib64/libc-2.12.so 53.00 1.3% Rf_findVarInFrame3 /usr/local/R/lib64/R/bin/exec/R 53.00 1.3% Rf_protect /usr/local/R/lib64/R/bin/exec/R 50.00 1.2% _IO_str_init_static_internal /lib64/libc-2.12.so 50.00 1.2% Rf_eval /usr/local/R/lib64/R/bin/exec/R 43.00 1.0% Rf_formatReal /usr/local/R/lib64/R/bin/exec/R 43.00 1.0% Rf_matchArgs /usr/local/R/lib64/R/bin/exec/R 41.00 1.0% _int_malloc /lib64/libc-2.12.so 36.00 0.9% _itoa_word /lib64/libc-2.12.so 33.00 0.8% __ieee754_log /lib64/libm-2.12.so 31.00 0.8% Rf_EncodeReal /usr/local/R/lib64/R/bin/exec/R 29.00 0.7% Rf_mkPROMISE /usr/local/R/lib64/R/bin/exec/R 29.00 0.7% do_bind /usr/local/R/lib64/R/bin/exec/R 28.00 0.7% Rf_install /usr/local/R/lib64/R/bin/exec/R 27.00 0.7% __vsnprintf /lib64/libc-2.12.so 27.00 0.7% _IO_no_init /lib64/libc-2.12.so 23.00 0.6% _IO_old_init /lib64/libc-2.12.so 22.00 0.5% __GI__nss_files_parse_servent /lib64/libnss_files-2.12.so 22.00 0.5% Rconn_printf /usr/local/R/lib64/R/bin/exec/R 22.00 0.5% finite /lib64/libm-2.12.so 22.00 0.5% findVarLocInFrame /usr/local/R/lib64/R/bin/exec/R 21.00 0.5% Rf_getAttrib /usr/local/R/lib64/R/bin/exec/R我懷疑
ulimit和``磁碟配額. After disabling the disk quota, the problem is still exist. Unfortunately, limits are equal under根and約翰. Here is the output ofulimit -a`（感謝@Eric DANNIELO）：# ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 127383 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) 1024 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited # su john $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 127383 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) 1024 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited作業系統：CentOS 6.2
硬體：Intel Core-i7 16GB RAM
先感謝您！
我不確定它是否相關，但你應該真正使用
su - john而不是su john: 那樣它將呼叫一個乾淨的登錄 shell。請檢查，這樣做，ulimit -a現在可能會顯示一些相關的差異嗎？另一件事：使用
strace -f R而不是strace R這樣當它呼叫子程序時，strace 也會跟踪該子程序並準確顯示該子程序的掛起位置。