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List:       kfm-devel
Subject:    Memory Usage
From:       Andreas Pour <pour () mieterra ! com>
Date:       2000-04-26 23:49:27
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Hi,

When viewing a not-so-realistic file -- like this:

<HTML>
<BODY>
11<BR>
 . . .  (repeat 11<BR> about 55,000 times)
11<BR>
</BODY>
</HTML> 

I noticed a couple of (well, three) strange things in Konqi.

First, it takes a long time -- about 20 seconds on a 350Mhz processor --
to open the file.  It takes vi about 1/10th of a second.  To quantify
this, I used vi to open this file:

	time vi test.html
	0.08user 0.01system 0:00.90elapsed 9%CPU (0avgtext+0avgdata
0maxresident)k

Then I used konqueror (3 tests):

	time konqueror test.html 
	24.43user 0.65system 0:30.07elapsed 83%CPU (0avgtext+0avgdata
0maxresident)k
	26.19user 0.66system 0:30.38elapsed 88%CPU (0avgtext+0avgdata
0maxresident)k
	24.67user 0.68system 0:28.76elapsed 88%CPU (0avgtext+0avgdata
0maxresident)k 

To shave off the overhead from starting konqueror (I restarted konqueror
each time), I ran konqueror with the same file as above, without the
extra 55,000 lines:
 
	3.33user 0.15system 0:09.00elapsed 38%CPU (0avgtext+0avgdata
0maxresident)k
	3.38user 0.13system 0:06.49elapsed 54%CPU (0avgtext+0avgdata
0maxresident)k
	3.28user 0.19system 0:08.00elapsed 43%CPU (0avgtext+0avgdata
0maxresident)k

Thus, it took 20 seconds of full CPU time to parse this file
(layout/rendering shouldn't take very long since no widgets are created
and the layout is very simple).  And since the great bulk of this time
is spent by kio_file loading the file, I don't know why konqi burns the
CPU on this.

Second, memory usage seemed somewhat excessive.  Starting konqueror with
the small test file:

  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND
 1554 pts/8    S      0:03   2372     2 15729 10676  8.3 konqueror
/tmp/tests.html

Using the large test file:

  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND 
 1563 pts/8    S      0:24   2380     2 44473 39452 30.8 konqueror
/tmp/test.html

So for a file of size 382,398 bytes, Konqi is using 30Mbytes of memory. 
I tried a medium test file of 5000 of the '11<BR>' lines (size = 35002
bytes) and memory usage was:

  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND 
 1954 pts/8    S      0:05   2939     2 18105 13048 10.2 konqueror
/tmp/testm.html

Plugging together my 3 data points, I get the rough formula:

	10.6MB + 70 * filesize

which seems a lot for a file with such a simple layout.

Just out of curiosity, I removed all the <BR>'s and put the 55,000 lines
of '11' between <PRE> tags, and the result was:

time konqueror /tmp/testp.html
7.86user 0.44system 0:14.31elapsed 57%CPU (0avgtext+0avgdata
0maxresident)k

and memory usage was:

  PID TTY      STAT   TIME  MAJFL   TRS   DRS  RSS %MEM COMMAND 
 1978 pts/8    S      0:07   2373     2 19617 14568 11.3 konqueror
/tmp/testp.html

So about 16 seconds faster and about 1/7th the memory consumption . . .
.


Third, the file is displayed strangely.  The first roughly 10% of the
lines have what appear to be two blobs in each line, which should be
1's.  The rest of the lines are empty -- it appears as if lines are
being drawn on top of each other, but offset horizontally a bit.  (The
small and medium files display correctly but the display with the <PR>
tags was even stranger -- 3 blobs per line for about the first 7% and
the rest of the lines empty).

Ciao,

Andreas

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