--- /dev/null
+#!/bin/bash
+# Demonstrate >5X speed-up in using fts-based rm on ext4
+# Demonstrate 1.5X speed-up in using fts-based rm on reiserfs
+
+set -x
+
+a=$(printf %031d 0)
+b=$(printf %031d 1)
+(mkdir $a \
+ && cd $a \
+ && seq --format=%031g 10000 |xargs touch \
+ && seq --format=d%030g 10000 |xargs mkdir ) || framework_failure
+cp -al $a $b || framework_failure
+mkdir e || framework_failure
+mv $a $b e || framework_failure
+
+cp -a e 1
+cp -a e 2
+
+sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+env time /p/bin/rm -rf 1
+env time /cu/src/rm -rf 2
+
+cp -a e 1
+cp -a e 2
+
+
+sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+env time cu/src/rm -rf 2
+env time /p/bin/rm -rf 1
+
+########################################################################
+# on ext4
+# + env time /p/bin/rm -rf 1
+# 0.19user 12.09system 0:14.42elapsed 85%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+212minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.13user 0.93system 0:01.08elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+1235minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + env time /cu/src/rm -rf 2
+# 0.12user 0.94system 0:01.07elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+1236minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.19user 12.08system 0:12.33elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+212minor)pagefaults 0swaps
+
+# on reiserfs:
+# + env time /p/bin/rm -rf 1
+# 0.30user 4.16system 0:04.49elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+168minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.21user 2.47system 0:02.88elapsed 93%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+80outputs (0major+1199minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + env time /cu/src/rm -rf 2
+# 0.19user 2.56system 0:02.76elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+1200minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.29user 4.17system 0:04.55elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+# 0inputs+0outputs (0major+168minor)pagefaults 0swaps
+
+########################################################################
+# on xfs, F11, slow-disk laptop: (shows slight improvement)
+# iou$ bash /cu/src/README-rm-timing-2 :
+# ++ printf %031d 0
+# + a=0000000000000000000000000000000
+# ++ printf %031d 1
+# + b=0000000000000000000000000000001
+# + mkdir 0000000000000000000000000000000
+# + cd 0000000000000000000000000000000
+# + xargs touch
+# + seq --format=%031g 10000
+# + seq --format=d%030g 10000
+# + xargs mkdir
+# + cp -al 0000000000000000000000000000000 0000000000000000000000000000001
+# + mkdir e
+# + mv 0000000000000000000000000000000 0000000000000000000000000000001 e
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /p/bin/rm -rf 1
+# 1.06user 12.10system 1:41.96elapsed 12%CPU (0avgtext+0avgdata 0maxresident)k
+# 16368inputs+0outputs (1major+175minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.57user 5.47system 1:32.69elapsed 6%CPU (0avgtext+0avgdata 0maxresident)k
+# 20112inputs+0outputs (1major+1214minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /cu/src/rm -rf 2
+# 0.54user 5.34system 1:28.43elapsed 6%CPU (0avgtext+0avgdata 0maxresident)k
+# 19032inputs+0outputs (1major+1198minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.99user 12.36system 1:37.36elapsed 13%CPU (0avgtext+0avgdata 0maxresident)k
+# 20256inputs+0outputs (1major+174minor)pagefaults 0swaps
+
+########################################################################
+# on btrfs, F11, slow-disk laptop: (shows 7-8X speed-up)
+# iou$ env time bash /cu/src/README-rm-timing-2 :
+# ++ printf %031d 0
+# + a=0000000000000000000000000000000
+# ++ printf %031d 1
+# + b=0000000000000000000000000000001
+# + mkdir 0000000000000000000000000000000
+# + cd 0000000000000000000000000000000
+# + seq --format=%031g 10000
+# + xargs touch
+# + seq --format=d%030g 10000
+# + xargs mkdir
+# + cp -al 0000000000000000000000000000000 0000000000000000000000000000001
+# + mkdir e
+# + mv 0000000000000000000000000000000 0000000000000000000000000000001 e
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /p/bin/rm -rf 1
+# 0.51user 59.42system 1:09.73elapsed 85%CPU (0avgtext+0avgdata 0maxresident)k
+# 43536inputs+82536outputs (1major+425minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.26user 8.01system 0:08.50elapsed 97%CPU (0avgtext+0avgdata 0maxresident)k
+# 808inputs+54984outputs (1major+1199minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# 0.26user 8.31system 0:09.17elapsed 93%CPU (0avgtext+0avgdata 0maxresident)k
+# 976inputs+47744outputs (1major+1197minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.48user 57.83system 1:04.81elapsed 89%CPU (0avgtext+0avgdata 0maxresident)k
+# 27408inputs+75632outputs (1major+423minor)pagefaults 0swaps
+# ---
+# 5.60user 214.36system 4:14.11elapsed 86%CPU (0avgtext+0avgdata 0maxresident)k
+# 131544inputs+551320outputs (83major+15945minor)pagefaults 0swaps
+
+########################################################################
+# on reiserfs, F11, slow-disk laptop: (shows ~4X speed-up)
+# but notice total test time: just 51s, compared with 4:11 for btrfs above.
+# iou$ env time bash /cu/src/README-rm-timing-2 :
+# ++ printf %031d 0
+# + a=0000000000000000000000000000000
+# ++ printf %031d 1
+# + b=0000000000000000000000000000001
+# + mkdir 0000000000000000000000000000000
+# + cd 0000000000000000000000000000000
+# + seq --format=%031g 10000
+# + xargs touch
+# + seq --format=d%030g 10000
+# + xargs mkdir
+# + cp -al 0000000000000000000000000000000 0000000000000000000000000000001
+# + mkdir e
+# + mv 0000000000000000000000000000000 0000000000000000000000000000001 e
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /p/bin/rm -rf 1
+# 0.48user 9.79system 0:10.33elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 256inputs+0outputs (1major+191minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.25user 2.15system 0:02.50elapsed 96%CPU (0avgtext+0avgdata 0maxresident)k
+# 808inputs+0outputs (1major+1198minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /cu/src/rm -rf 2
+# 0.26user 2.10system 0:02.46elapsed 95%CPU (0avgtext+0avgdata 0maxresident)k
+# 808inputs+0outputs (1major+1198minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.44user 9.89system 0:10.41elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+# 264inputs+0outputs (1major+176minor)pagefaults 0swaps
+# ---
+# 4.48user 42.92system 0:51.14elapsed 92%CPU (0avgtext+0avgdata 0maxresident)k
+# 21680inputs+54232outputs (86major+16962minor)pagefaults 0swaps
+
+########################################################################
+# on ext2, F11, slow-disk laptop: (shows ~4X speed-up)
+# iou$ env time bash /cu/src/README-rm-timing-2 :
+# ++ printf %031d 0
+# + a=0000000000000000000000000000000
+# ++ printf %031d 1
+# + b=0000000000000000000000000000001
+# + mkdir 0000000000000000000000000000000
+# + cd 0000000000000000000000000000000
+# + seq --format=%031g 10000
+# + xargs touch
+# + seq --format=d%030g 10000
+# + xargs mkdir
+# + cp -al 0000000000000000000000000000000 0000000000000000000000000000001
+# + mkdir e
+# + mv 0000000000000000000000000000000 0000000000000000000000000000001 e
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /p/bin/rm -rf 1
+# 1.02user 15.25system 0:30.76elapsed 52%CPU (0avgtext+0avgdata 0maxresident)k
+# 178888inputs+19144outputs (1major+423minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.40user 2.30system 0:05.99elapsed 45%CPU (0avgtext+0avgdata 0maxresident)k
+# 83088inputs+18480outputs (1major+1199minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /cu/src/rm -rf 2
+# 0.38user 2.83system 0:08.18elapsed 39%CPU (0avgtext+0avgdata 0maxresident)k
+# 85848inputs+16024outputs (1major+1199minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.84user 15.24system 0:25.28elapsed 63%CPU (0avgtext+0avgdata 0maxresident)k
+# 178656inputs+18728outputs (1major+423minor)pagefaults 0swaps
+# ---
+# 6.73user 263.32system 5:27.69elapsed 82%CPU (0avgtext+0avgdata 0maxresident)k
+# 780296inputs+891712outputs (86major+17155minor)pagefaults 0swaps
+
+########################################################################
+# on tmpfs, F11, slow-disk laptop: (shows ~4X speed-up)
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /p/bin/rm -rf 1
+# 0.37user 2.47system 0:03.10elapsed 91%CPU (0avgtext+0avgdata 0maxresident)k
+# 256inputs+0outputs (1major+175minor)pagefaults 0swaps
+# + env time /cu/src/rm -rf 2
+# 0.23user 0.41system 0:00.76elapsed 85%CPU (0avgtext+0avgdata 0maxresident)k
+# 520inputs+0outputs (1major+2092minor)pagefaults 0swaps
+# + cp -a e 1
+# + cp -a e 2
+# + sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
+# + env time /cu/src/rm -rf 2
+# 0.24user 0.41system 0:00.73elapsed 89%CPU (0avgtext+0avgdata 0maxresident)k
+# 800inputs+0outputs (1major+2090minor)pagefaults 0swaps
+# + env time /p/bin/rm -rf 1
+# 0.36user 2.47system 0:02.86elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+# 256inputs+0outputs (1major+175minor)pagefaults 0swaps
--- /dev/null
+==================================================
+[SSD: it's a toss-up, when removing a million-file (1000 per dir) tree
+on (sdd-ocz-summit-120G, F11, x86_64, lots of RAM)
+$ z-mktree --root=z --depth=2 --b=1000;env time /p/bin/rm -rf z
+0.50user 13.99system 0:17.83elapsed 81%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+10834minor)pagefaults 0swaps
+$ z-mktree --root=z --depth=2 --b=1000;env time src/rm -rf z
+0.52user 13.88system 0:17.41elapsed 82%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+8outputs (0major+10835minor)pagefaults 0swaps
+
+==================================================
+on (tmpfs, F11, x86_64, lots of RAM)
+/t, with very deep, narrow tree, new rm is >20% faster:
+$ z-mkdir 1000000
+$ env time /p/bin/rm -rf $TMPDIR/z
+6.25user 12.88system 0:19.22elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+70976minor)pagefaults 0swaps
+$ z-mkdir 1000000
+env time /bin/rm -rf $TMPDIR/z
+$ env time /bin/rm -rf $TMPDIR/z
+11.06user 14.32system 0:25.43elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+56inputs+0outputs (1major+79999minor)pagefaults 0swaps
+
+*** slow*DOWN* of ~4% on a 1-1Kdir-1M-file (1k-files-per-dir) hierarchy
+again, this is on tmpfs:
+$ z-mktree --root=/t/z --depth=2 --b=1000;strace -c /p/bin/rm -rf /t/z
+vv$ z-mktree --root=/t/z --depth=2 --b=1000;env time /cu/src/rm -rf /t/z
+0.29user 2.75system 0:03.06elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+10834minor)pagefaults 0swaps
+$ z-mktree --root=/t/z --depth=2 --b=1000;env time /p/p/coreutils-7.5/bin/rm -rf /t/z
+0.14user 2.76system 0:02.92elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+184minor)pagefaults 0swaps
+
+
+==================================================
+
+[old rm]
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;strace -c /p/bin/rm -rf /t/z
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 90.66 0.086370 0 1001002 1 unlinkat
+ 8.72 0.008310 1 10002 getdents64
+ 0.22 0.000214 0 2001 openat
+ 0.20 0.000188 0 2021 close
+ 0.09 0.000089 0 6019 fstat64
+ 0.08 0.000073 0 6003 fcntl64
+ 0.03 0.000028 1 29 12 open
+ 0.00 0.000000 0 4 read
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 1000 lseek
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 3 brk
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 2 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 19 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1 fstatat64
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.095272 1028117 16 total
+
+
+[new, fts-based rm]
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;strace -c ./rm -rf /t/z
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 95.88 0.122730 0 1001001 unlinkat
+ 3.95 0.005058 1 7007 getdents64
+ 0.10 0.000126 0 2022 close
+ 0.05 0.000064 0 1001 openat
+ 0.02 0.000020 0 1017 fstat64
+ 0.00 0.000000 0 4 read
+ 0.00 0.000000 0 29 12 open
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 510 brk
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 2 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 19 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 3003 fcntl64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1001 fstatat64
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.127998 1016627 15 total
+iou$ export LC_ALL=C cu:198-rm-fts
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;strace -c ./rm -rf /t/z
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 93.49 0.110607 0 1001001 unlinkat
+ 6.32 0.007475 1 7007 getdents64
+ 0.10 0.000124 0 1001 fstatat64
+ 0.06 0.000068 0 479 brk
+ 0.02 0.000018 0 2008 close
+ 0.01 0.000015 0 3003 fcntl64
+ 0.00 0.000000 0 2 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 6 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 1003 fstat64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1001 openat
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.118307 1016526 3 total
+
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;strace -c /p/bin/rm -rf /t/z
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 92.87 0.107659 0 1001002 1 unlinkat
+ 6.59 0.007641 1 10002 getdents64
+ 0.22 0.000252 0 2001 openat
+ 0.15 0.000179 0 6005 fstat64
+ 0.10 0.000113 0 6003 fcntl64
+ 0.05 0.000054 0 1000 lseek
+ 0.02 0.000027 0 2007 close
+ 0.00 0.000000 0 2 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 3 brk
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 6 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1 fstatat64
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.115925 1028047 4 total
+
+**********************************************************************
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time /p/bin/rm -rf /t/z
+0.16user 3.35system 0:03.68elapsed 95%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+166minor)pagefaults 0swaps
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time /p/bin/rm -rf /t/z
+0.16user 3.12system 0:03.34elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+166minor)pagefaults 0swaps
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time /p/bin/rm -rf /t/z
+0.14user 3.12system 0:03.26elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+167minor)pagefaults 0swaps
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time /p/bin/rm -rf /t/z
+0.12user 2.98system 0:03.17elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+167minor)pagefaults 0swaps
+
+
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time ./rm -rf /t/z
+0.68user 3.08system 0:03.76elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+1566minor)pagefaults 0swaps
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time ./rm -rf /t/z
+0.64user 3.12system 0:03.79elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+1565minor)pagefaults 0swaps
+iou$ z-mktree --root=/t/z --depth=2 --b=1000;env time ./rm -rf /t/z
+0.60user 3.09system 0:03.78elapsed 97%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+1566minor)pagefaults 0swaps
+
+************************************************************************
+************************************************************************
+
+The above are relatively normal hierarchies.
+Here is one that is extreme (/t is a tmpfs file system):
+[shows that fts-based rm takes 20-25% more time than the old one]
+
+iou$ mkdir .j && (cd .j && seq 1000000|xargs touch)
+
+iou$ env time ./rm -rf /t/.j cu:198-rm-fts
+0.10user 0.41system 0:00.59elapsed 87%CPU (0avgtext+0avgdata 0maxresident)k
+256inputs+0outputs (1major+4459minor)pagefaults 0swaps
+iou$ env time ./rm -rf /t/.j cu:198-rm-fts
+0.82user 3.48system 0:04.35elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+256inputs+0outputs (1major+43130minor)pagefaults 0swaps
+iou$ env time /p/bin/rm -rf /t/.j cu:198-rm-fts
+0.14user 3.02system 0:03.25elapsed 97%CPU (0avgtext+0avgdata 0maxresident)k
+256inputs+0outputs (1major+164minor)pagefaults 0swaps
+iou$ env time strace -c /p/bin/rm -rf /t/.j cu:198-rm-fts
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 95.49 0.122568 0 1000002 1 unlinkat
+ 4.51 0.005785 1 7797 getdents64
+ 0.00 0.000000 0 2 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 7 close
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 1 lseek
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 3 brk
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 6 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 5 fstat64
+ 0.00 0.000000 0 3 fcntl64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1 fstatfs64
+ 0.00 0.000000 0 1 openat
+ 0.00 0.000000 0 1 fstatat64
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.128353 1007844 4 total
+2.96user 21.57system 0:24.80elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+8inputs+0outputs (0major+406minor)pagefaults 0swaps
+iou$ env time strace -c ./rm -rf /t/.j cu:198-rm-fts
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 83.46 0.160976 0 1000001 unlinkat
+ 14.54 0.028036 21 1306 brk
+ 2.01 0.003873 0 7795 getdents64
+ 0.00 0.000000 0 2 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 8 close
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 3 3 access
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 4 mprotect
+ 0.00 0.000000 0 6 mmap2
+ 0.00 0.000000 0 1 lstat64
+ 0.00 0.000000 0 3 fstat64
+ 0.00 0.000000 0 3 fcntl64
+ 0.00 0.000000 0 1 set_thread_area
+ 0.00 0.000000 0 1 fstatfs64
+ 0.00 0.000000 0 1 openat
+ 0.00 0.000000 0 1 fstatat64
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.192885 1009142 3 total
+3.86user 22.06system 0:26.30elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+43371minor)pagefaults 0swaps
+
+======================================================
+# On a faster system, the new fts-based rm still takes a 20% perf. hit,
+# probably due to malloc (ab)use, just like above. Yep, sure looks like it.
+# in /tmpfs, /t
+mkdir .j && (cd .j && seq 1000000|xargs touch)
+vv$ env time /p/p/coreutils-7.5/bin/rm -rf .j
+0.14user 2.81system 0:02.98elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+264inputs+0outputs (1major+174minor)pagefaults 0swaps
+vv$ cd /t; env time /cu/src/rm -rf .j
+0.38user 3.17system 0:03.57elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
+0inputs+0outputs (0major+70489minor)pagefaults 0swaps
+
+vv$ strace -c /p/p/coreutils-7.5/bin/rm -rf .j
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 66.41 0.081223 0 1000002 1 unlinkat
+ 33.43 0.040887 42 978 getdents
+ 0.16 0.000199 199 1 execve
+ 0.00 0.000000 0 1 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 7 close
+ 0.00 0.000000 0 6 fstat
+ 0.00 0.000000 0 1 lstat
+ 0.00 0.000000 0 1 lseek
+ 0.00 0.000000 0 9 mmap
+ 0.00 0.000000 0 3 mprotect
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 3 brk
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 1 access
+ 0.00 0.000000 0 3 fcntl
+ 0.00 0.000000 0 1 fstatfs
+ 0.00 0.000000 0 1 arch_prctl
+ 0.00 0.000000 0 1 openat
+ 0.00 0.000000 0 1 newfstatat
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.122309 1001025 2 total
+
+
+vv$ cd /t; strace -c /cu/src/rm -rf .j
+% time seconds usecs/call calls errors syscall
+------ ----------- ----------- --------- --------- ----------------
+ 51.26 0.087638 0 1000001 unlinkat
+ 26.49 0.045291 46 976 getdents
+ 22.24 0.038024 18 2134 brk
+ 0.00 0.000000 0 1 read
+ 0.00 0.000000 0 3 open
+ 0.00 0.000000 0 8 close
+ 0.00 0.000000 0 4 fstat
+ 0.00 0.000000 0 1 lstat
+ 0.00 0.000000 0 9 mmap
+ 0.00 0.000000 0 3 mprotect
+ 0.00 0.000000 0 1 munmap
+ 0.00 0.000000 0 1 ioctl
+ 0.00 0.000000 0 1 1 access
+ 0.00 0.000000 0 1 execve
+ 0.00 0.000000 0 3 fcntl
+ 0.00 0.000000 0 1 fstatfs
+ 0.00 0.000000 0 1 arch_prctl
+ 0.00 0.000000 0 1 openat
+ 0.00 0.000000 0 1 newfstatat
+------ ----------- ----------- --------- --------- ----------------
+100.00 0.170953 1003151 1 total
projects / thirdparty / coreutils.git / commitdiff
