Veerapuram Varadhan’s worklog

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Evolution Exchange Performance Series – Chapter 1 – Folder Loading

Posted by vvaradhan on August 11, 2006

One of the critical issues in exchange mailer is – time spent to load the hierarchy or mail folders. See this graph: Exchange mailer folder loading graph

It clearly shows most of time is spent in constructing folder objects. The sample size used to generate this graph is two folders with 210 and 50 mails repectively. Patch extends Federico’s sample code and implements different levels of checkpoints. Graph on the left hand side is generated using a E2K_LOG_LEVEL=1.

As I mentioned in my previous blog, this is the customized plot-timeline script that generated this image.

Posted in Evolution, Exchange, Performance | 3 Comments »

Evolution – Exchange connector

Posted by vvaradhan on August 11, 2006

A new feather got added to my cap of responsibilities w.r.t evolution, viz., Exchange connector – one of the distinguishing features of mighty Evolution. My responsibilities for Exchange connector ranges from fixing some critical customer issues to performance, scalability and stability of the module. One of the key problems with exchange module is performance. Initial loading of folders takes huge amount of time as compared to IMAP/POP/GW. After reading through quite a lot of tutorials and blogs, I came across Federico‘s blog about how strace can be helpfull for profiling with minimum coding.

Took the sample code from Federico‘s blog and extended it a little bit to have different levels to avoid too many messages and included thread-ids to group the messages. I have also customized the plot-timeline script to group by thread-id. Will upload the patch and the graph, generated by the script, later.

Time to catch some sleep now.

Posted in Email, Evolution, GNOME, PIM, Technical | 1 Comment »

Spotlight

Posted by vvaradhan on July 14, 2006

Lot many things have happened since my last blog. I am now a full-time Evolution Mail hacker and precisely the New Mail Maintainer for Evolution. Sounds thrilling, ain’t it? 😉 We are just finished with our SLED10 that we, in Novell, have been working sleeplessly for the past few months and the results are fantastic. Just check out why people love it, here.

Thats the quick update on what I am currently into. Lets run through the various other things, quickly:

LDTP, my passion and a project headed by my buddy, Nagappan, received a Google SoC through GNOME and Prashanth Mohan is already knocking it out.

The SoC proposal consists of three milestones: LDTP integration with jhautobuild, Evolution automation and LDTP Regression suite and Prashanth has started working on the second milestone and tinderbox integration is on the final stages to get upstream. For those interested, the log of a real test, run on the test server provided by Frederic Peters is here and a detailed log is here.

Two students, sp2hari and taggy from NIT, Trichy, spent 6 weeks as intern, as part of NOSIP, work like mad and contributed an awesome tool for LDTP called Record. Record captures the user actions on any application and generates a LDTP test script that can be played back. This makes generating-test-scripts easier – simply, automated test-script generation.

Evolution
After a mammoth effort by the team and the community, Evolution 2.6 is stable and sleeker than its previous versions.

Recently, Phillip Vanhoof came up with the idea of mmap()’ing CamelFolderSummary instead of fread’ing it. We had around 2 hours of discussion and shared my experiences on CamelFolderSummary and other related things that he should consider when implementing mmap(). He has some 12 versions of patches and is close to what I asked for. Kudos!! Phillip.

However, the behaviour of the patch is yet to be analysed on various other scenarios: Couple of them are 1) When messages are deleted, 2) When message flags are changed.. etc.

Moreover, before taking upstream, the patch should be tested on a decent sample size using evolution and all the folder operations should be verified. Also, the patch should give a choice to the user/application to choose between mmap() and fread(). Guess, with said final touches it should make it upstream. Phillip? 😉

That’s all for now.. stay tuned!!

Posted in Uncategorized | 1 Comment »

3rd Top in closing most bugs for last week

Posted by vvaradhan on May 31, 2006

I was playing around in bugzilla creating more saved-searches for quicker access to bugs and found my name listed 3rd for closing most number of bugs in last 7 days on Past week’s bug activity link in Gnome bugzilla.

As the link for past-week’s-bug-activity keeps changing, here is the list of bugs that I closed, includes evolution-conduits, beagle, connector, gnome-pilot and GAL bugs.

Posted in Uncategorized | 1 Comment »

Recurrence – Mind blowing stuff of iCal – 2

Posted by vvaradhan on May 31, 2006

Today I committed my recurrence work in evolution-exchange along with other conduit patches. Now, evolution-conduits can sync against exchange and groupwise (needs testing) accounts.

Following links will take you to those committed changes:
1) Calendar conduit
2) Todo conduit
3) Addressbook conduit
4) Recurrence fix in evolution-exchange

Now, that Eureka thing. Yes, the bug was in exchange-calendar code that reads events from the server. According to MSDN, events have some specific property that has values from 0 – 4, which represents events with master object, without master object, detached instances etc. Evolution-exchange was always querying for events with codes 0 and 1, which made the message not to appear in evolution as it didn’t even fetch. Chen fixed this thing today.

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Bug triaging – Part 1

Posted by vvaradhan on May 31, 2006

Last week I triaged around 36 bugs in GAL, which is now a retired-component of Evolution. Have to categorize that list of bugs in to fix-for-gods-sake, fix-for-goodness-sake and wont-fix.

Today, triaged around 80 bugs in all including Evolution-conduits, gpilot and Beagle.

Marked around 20 bugs as FIXED/INCOMPLETE/NOTGNOME and 30 bugs to be fixed.

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Recurrence – Mind blowing stuff of iCal

Posted by vvaradhan on May 31, 2006

The supplemental patch had a new FIXME to support syncing of instances of a calendar event. In simpleton, recurrences. Recurrence in Evolution has always been a nightmare and especially w.r.t individual backends its more than a nightmare. Chen had made quite good contributions for recurrence in evolution-data-server and some of the other backends. My synchronization stuff cannot be close to complete, if I don’t have support for syncing the instances of a recurrence. Today, with a determined mind, was looking at the other backends for similar implementation and finally, got the code in place.

Testing is what makes us happy to see our code working. Well, it was working except for a specific scenario in which we have only (a) instance(s) without any corresponding master object. Hugh… I was tired finding out the roots of the cause and finally got to a point where I could say, “Eureka!! I found the reason”. Well, thatz it for today and keep watching to know more about that “Eureka” stuff. 😉

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Beagle memory optimization – Filters

Posted by vvaradhan on May 31, 2006

On 26th November 2005, myself and Debajyothi Bera started discussing about memory consumption of Beagle, especially its filters. DBera gave a link to the heap-buddy output of Source filter, which showed around 2.9M of allocations.

I immediately pulled heap-buddy from the trunk and installed it and ran beagle-extract-content on a ‘C#’ source-code file of size approx. 130K. The report showed around 2.6M of allocations for extracting contents from that ‘C#’ file and the size of extracted content was just around 68K. Here is the heap-buddy output before fix:

bhargavi@vvaradhan-lap:~/cvs/beagle/beagle-before-fix/beagled> heap-buddy outfile
SUMMARY

Filename: outfile
Allocated Bytes: 2.6M
Allocated Objects: 68736
GCs: 10
Resizes: 8
Final heap size: 1.3M

Distinct Types: 170
Backtraces: 2572

and individual “type-based-allocations” as follows…

bhargavi@vvaradhan-lap:~/cvs/beagle/beagle-before-fix/beagled> heap-buddy outfile types

Type # Total AvSz AvAge BT#
string 44744 2.0M 47.4 0.2 636
string[] 4460 106k 24.4 0.1 59
char[] 3922 98k 25.7 0.3 59
char 7141 69k 10.0 0.0 8
System.Text.StringBuilder 1940 45k 24.0 0.0 71
System.Collections…t/SimpleEnumerator 1339 31k 24.0 0.0 17
byte[] 21 29k 1422.7 5.6 21
System.Collections.Hashtable/Slot[] 106 26k 251.2 1.8 71
object[] 321 23k 76.2 0.7 182
Beagle.Filters.FilterHtml 695 21k 32.0 3.9 1
System.MonoType 650 16k 25.7 8.1 166
System.Reflection.MonoMethod 293 11k 41.0 7.8 20
System.Xml.NameTable/Entry[] 20 10k 528.0 0.1 13
System.Xml.NameTable/Entry 226 5.3k 24.0 0.4 94
System.IO.FileInfo 65 5.1k 80.0 1.1 2
System.Collections.ArrayList 255 5.0k 20.0 0.8 154
System.Xml.XmlName…eManager/NsScope[] 15 4.9k 336.0 0.1 8
System.Reflection.PropertyInfo[] 116 4.6k 40.9 0.0 10
System.Collections.Hashtable 93 4.4k 48.0 2.1 62
System.Reflection.MethodInfo[] 20 3.9k 199.6 0.0 3
System.Attribute[] 197 3.6k 18.6 0.4 66
System.Xml.Serialization.XmlAttributes 55 3.2k 60.0 0.3 25
System.MonoType[] 201 3.1k 16.0 6.0 8
System.Reflection.MonoCMethod 125 2.6k 21.5 5.3 6
System.Xml.Serialization.TypeData 58 2.5k 44.0 8.9 57

(skipped 145 types)

… check the top 4 types.. string, string[], char, char[] and StringBuilder. These are the types that contributed most of allocations.

A little closer look at the Filter.cs revealed a potential-unnecessary-allocation of string being done. The fix here fixed it. The fix saved around 600K of allocations for filtering the mentioned “C#” file.

Heap-buddy report after the fix:

bhargavi@vvaradhan-lap:~/cvs/beagle/beagle/beagled> heap-buddy outfile

SUMMARY

Filename: outfile
Allocated Bytes: 2.0M
Allocated Objects: 47082
GCs: 8
Resizes: 8
Final heap size: 1.3M

Distinct Types: 170
Backtraces: 2581

.. and “individual-type-based-allocations”..
bhargavi@vvaradhan-lap:~/cvs/beagle/beagle/beagled> heap-buddy outfile types

Type # Total AvSz AvAge BT#
string 32361 1.6M 50.8 0.2 639
char 7141 69k 10.0 0.0 8
char[] 218 33k 157.3 4.4 54
System.Collections…t/SimpleEnumerator 1334 31k 24.0 0.0 17
byte[] 21 29k 1422.7 4.4 21
string[] 685 27k 40.9 0.6 55
System.Collections.Hashtable/Slot[] 107 26k 250.3 1.4 72
object[] 319 23k 75.7 0.6 182
Beagle.Filters.FilterHtml 734 22k 31.6 3.2 1
System.MonoType 652 16k 25.6 6.4 166
System.Reflection.MonoMethod 293 11k 41.0 6.1 20
System.Xml.NameTable/Entry[] 20 10k 528.0 0.1 13
System.Xml.NameTable/Entry 226 5.3k 24.0 0.4 94
System.Collections.ArrayList 253 4.9k 20.0 0.6 152
System.Xml.XmlName…eManager/NsScope[] 15 4.9k 336.0 0.1 8
System.Reflection.PropertyInfo[] 116 4.6k 40.9 0.0 10
System.IO.FileInfo 57 4.5k 80.0 0.1 2
System.Collections.Hashtable 94 4.4k 48.0 1.6 63
System.Reflection.MethodInfo[] 20 3.9k 199.6 0.0 3
System.Attribute[] 197 3.6k 18.6 0.3 66
System.Xml.Serialization.XmlAttributes 55 3.2k 60.0 0.3 25
System.MonoType[] 202 3.2k 16.0 4.5 8
System.Text.StringBuilder 127 3.0k 24.0 0.2 85
System.Reflection.MonoCMethod 122 2.6k 21.5 4.3 6
System.Xml.Serialization.TypeData 58 2.5k 44.0 6.9 57

(skipped 145 types)

When you compare the above two reports, the main contributors for memory allocations were reduced after fix.

The current fix will give some good numbers when run on bigger documents. (Will post them later.)

As a side-effect of this fix, the filters run little faster than they used to be. 😉

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Exchange synchronization is back.

Posted by vvaradhan on May 31, 2006

Just cooked up a patch for todo-conduits to sync with exchange-tasks. All the three, Calendar, Tasks and Addressbook (contact) conduits are now authentication aware that they can authenticate without user interaction. However, user should have saved their account passwords through Evolution.

Patches are as follows:
Calendar and Contacts
Tasks
Supplemental fix for exchange-calendar sync to work. 😉

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Dtrace and glib

Posted by vvaradhan on May 31, 2006

Memory leaks have always been difficult problems to deal it. There are many tools available and most of them preloads the probes and thus adds overhead on the execution of software.

During recent encounters with memory leaks, I thought of trying DTrace, the dynamic tracing tool available from Solaris. It operates on the kernel level probes and thus doesn’t add overhead by preloading probes during execution. It took me a while to get the setup ready for a noble cause. 😉

And bingo!!, got a dtrace script and a supporting perl script that ease the job of printing the stack that leaks memory. Both the scripts are available here. The output of the script was quite satisfactory, however, glib uses memory-pools that doesn’t actually free the memory, rather, mark it for re-use and similarly, its allocation routines return pointers from the pool, when available otherwise allocates fresh memory and maintain it in the pool.

The DTrace script in the link actually uses the standard syscall probes, which in this case wouldn’t be appropriate. So, I came up with the following script for glib:

#!/usr/sbin/dtrace -s

pid$target:libglib-2.0.so.0:g_malloc:entry
{
   self->trace = 1;
   self->size = arg0;
}
pid$target:libglib-2.0.so.0:g_malloc:return
/self->trace == 1/
{
   printf("Ptr=0x%p Size=%d", arg1, self->size);
   ustack();
   self->trace = 0;
   self->size = 0;
}

pid$target:libglib-2.0.so.0:g_realloc:entry
{
   self->trace = 1;
   self->size = arg1;
   self->oldptr = arg0;
}

pid$target:libglib-2.0.so.0:g_realloc:return
/self->trace == 1/
{
   printf("Ptr=0x%p Oldptr=0x%p Size=%d", arg1, self->oldptr,
self->size);
   ustack();
   self->trace = 0;
   self->size = 0;
}

pid$target:libglib-2.0.so.0:g_malloc0:entry
/self->trace == 1/
{
   self->trace = 1;
   self->size = arg1;
}

pid$target:libglib-2.0.so.0:g_malloc0:return
/self->trace == 1/
{
   printf("Ptr=0x%p Size=%d", arg1, self->size);
   ustack();
   self->trace = 0;
   self->size = 0;
}

pid$target:libglib-2.0.so.0:g_free:entry
{
   printf("Ptr=0x%p ", arg0);
}

The test program to verify the script:

#include 
#include 

int
main ()
{
gchar* str = NULL;
int i;

for (i = 0; i 

DTrace reported “Zero” memory leaks and I sort of convinced that the script works and can be run on bigger application like Evolution.

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