Re: SSHFS makes the ROOT launch speed slow?

Hello Axel and all,

I am using Mac OS X which does not have strace. Does anyone know a good alternative tool to trace file I/O in root.exe?

Regards,

--
OKUMURA, Akira oxon@{astro.isas.jaxa.jp,stanford.edu}
Institute of Space and Astronautical Science (ISAS/JAXA)
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On 2011/02/03, at 5:47, Axel Naumann wrote:

> Hi,
> 
> run strace on root.exe (yes, on Linux). root invokes root.exe, and I
> believe that's what you are seeing.
> 
> Cheers, Axel.
> 
> Eduard Avetisyan wrote on 02/02/2011 08:55 PM:


>> 

>> 

>> On Wed, 2 Feb 2011, Konstantin Olchanski wrote:

>> 

>>> On Wed, Feb 02, 2011 at 08:34:52PM +0100, Eduard Avetisyan wrote:
>>>>> On Wed, Feb 02, 2011 at 08:04:12PM +0100, Eduard Avetisyan wrote:
>>>>>> 
>>>>>> The same strace produces ~130 calls in my case, which include but are not 
>>>>>> limited to libraries like:
>>>>>> open("tls/i686/sse2/libXpm.so.4", O_RDONLY) = -1 ENOENT (No such file or directory)
>>>>> 
>>>>> You have "." in your LD_LIBRARY_PATH. Remove it and those syscalls will go away.
>>>> 
>>>> Good hint! Changing the LD_LIBRARY_PATH from ":$ROOTSYS/lib" to simply 
>>>> "$ROOTSYS/lib" (just a colon difference) reduced the startup time from 12s 
>>>> to 8s, so by 1/3. Still, it's way slower than a local startup time of 0.1s. 
>>>> 
>>> 
>>> You are still making the system search for every system library in $ROOTSYS/lib,
>>> which I understand is a slow SSHFS filesystem.


>> 

>> Quite the contrary! The $ROOTSYS is local and fast! Only the current 

>> working directory is on SSHFS! 

>> 

>> 

>>> 
>>> You can try to put the system library path (/lib, etc) in front of $ROOTSYS/lib,
>>> so the loader quickly finds the system libraries and does not touch SSHFS.


>> Tried, doesn't change anything (as $ROOTSYS is local anyway). But I found 

>> that the slow part happens with the following strace signature:

>> 

>> clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb73769b8) = 27680

>> waitpid(27680, root [0] [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], WSTOPPED) = 27680

>> 

>> namely, "waitpid(27680," is printed and the rest shows up 8-12 seconds 

>> later. 

>> 

>> Thanks for looking into this!

>> 	Eduard

>>> 
>>> -- 
>>> Konstantin Olchanski
>>> Data Acquisition Systems: The Bytes Must Flow!
>>> Email: olchansk-at-triumf-dot-ca
>>> Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada
>>> 
>>> 


>> 

>