Question

My question is similar to

• Why does Cygwin execute shell commands very slowly?
• Cygwin's bash became extremely slow after errors

I think my problem is caused by a different issue though.

Here is an example of extremely slow commands in Cygwin:

time for i in {1..10} ; do bash -c "echo Hello" ; done

Hello
...

real    0m21.588s
user    0m0.458s
sys     0m0.989s

Something is causing this… but what could it be?

Things that I have tried:

• Disabling windows firewall and windows security essentials.
• I don’t have any other antivirus products.
• I tried killing different user processes to see if any of them could be interfering – no luck.
• I’m not connected to any network.
• If I run the commands in C:\cygwin\bin via windows CMD, e.g. C:\cygwin\bin\ls.exe, they are still slow.

I then tried running this command to get a better idea of what’s going on:

strace -o bash.strace bash -c "echo hello"

From what I can see there is one row that was taking 90% of the time:

(in case it’s not clear it is the row starting with 1028210 – I included the other rows for context)

  5       5 [main] bash 1088 open_shared: name shared.5, n 5, shared 0x60FB0000 (wanted 0x60FB0000), h 0x74C
208     213 [main] bash 1088 heap_init: heap base 0x530000, heap top 0x530000
118     331 [main] bash 1088 open_shared: name S-1-5-21-2025429265-1957994488-1801674531-1003.1, n 1, shared 0x60FC0000 (wanted 0x60FC0000), h 0x748
 85     416 [main] bash 1088 user_info::create: opening user shared for 'S-1-5-21-2025429265-1957994488-1801674531-1003' at 0x60FC0000
 83     499 [main] bash 1088 user_info::create: user shared version 6112AFB3
344     843 [main] bash 1088 dll_crt0_0: finished dll_crt0_0 initialization
283    1126 [main] bash 1088 _cygtls::remove: wait 0xFFFFFFFF
 87    1213 [main] bash 1088 _cygtls::remove: removed 0x23CE64 element 0
104    1317 [main] bash 1088 _cygtls::remove: wait 0xFFFFFFFF
 70    1387 [main] bash 1088 _cygtls::remove: removed 0x23CE64 element 0
102    1489 [main] bash 1088 _cygtls::remove: wait 0xFFFFFFFF
 70    1559 [main] bash 1088 _cygtls::remove: removed 0x23CE64 element 0
110    1669 [main] bash 1088 _cygtls::remove: wait 0xFFFFFFFF
 70    1739 [main] bash 1088 _cygtls::remove: removed 0x23CE64 element 0
781    2520 [main] bash 1088 _cygtls::remove: wait 0xFFFFFFFF
 76    2596 [main] bash 1088 _cygtls::remove: removed 0x23CE64 element 0
278    2874 [sig] bash 1088 wait_sig: entering ReadFile loop, my_readsig 0x72C, my_sendsig 0x728
1028210 1031084 [main] bash 1088 mount_info::conv_to_posix_path: conv_to_posix_path (C:\cygwin\home\Adam, no-keep-rel, no-add-slash)
107 1031191 [main] bash 1088 normalize_win32_path: C:\cygwin\home\Adam = normalize_win32_path (C:\cygwin\home\Adam)
 59 1031250 [main] bash 1088 mount_info::conv_to_posix_path: /home/Adam = conv_to_posix_path (C:\cygwin\home\Adam)
11535 1042785 [main] bash 1088 _cygwin_istext_for_stdio: fd 0: not open
 69 1042854 [main] bash 1088 _cygwin_istext_for_stdio: fd 1: not open
 62 1042916 [main] bash 1088 _cygwin_istext_for_stdio: fd 2: not open
360 1043276 [main] bash (1088) open_shared: name cygpid.1088, n 1088, shared 0x60FE0000 (wanted 0x60FE0000), h 0x678
 65 1043341 [main] bash 1088 **********************************************
 46 1043387 [main] bash 1088 Program name: C:\cygwin\bin\bash.exe (pid 1088, ppid 1)
 46 1043433 [main] bash 1088 App version:  1007.7, api: 0.230
 45 1043478 [main] bash 1088 DLL version:  1007.9, api: 0.237
 46 1043524 [main] bash 1088 DLL build:    2011-03-29 10:10
 51 1043575 [main] bash 1088 OS version:   Windows NT-5.1
 45 1043620 [main] bash 1088 Heap size:    402653184
 45 1043665 [main] bash 1088 **********************************************
 45 1043710 [main] bash 1088 pinfo::thisproc: myself->dwProcessId 1088
 50 1043760 [main] bash 1088 time: 1321506515 = time (0)
862 1044622 [main] bash 1088 parse_options: glob (called func)
 78 1044700 [main] bash 1088 parse_options: returning
 45 1044745 [main] bash 1088 environ_init: GetEnvironmentStrings returned 0x10000
 ...

I don’t really understand what problem the offending line could be alluding to:

mount_info::conv_to_posix_path: conv_to_posix_path (C:\cygwin\home\Adam, no-keep-rel, no-add-slash)

How can I debug this issue further? Does anyone have any ideas?

Answer 1

Since updating to the latest Cygwin (v2.769), this is much less of an issue. (Previously I was using v2.738 I think)

Under 2.769, the same command gives much better results:

$ time for i in {1..10} ; do bash -c "echo Hello" ; done
Hello
...

real    0m0.641s
user    0m0.379s
sys     0m0.506s

Cygwin is still slower than I would like – I mainly use it for git and vim, and both of those are much slower than their native counterparts.

But it is at least much more usable now.