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Full Discussion: select vs poll
Special Forums IP Networking select vs poll Post 302115890 by porter on Sunday 29th of April 2007 06:42:27 PM
Old 04-29-2007
Quote:
Originally Posted by smanu
.... if there is any real performance boost
Rarely does merely switching versions give you a huge performance boost.

I suggest you look at your application architecture and look for bottlenecks.

1. Do you use non-blocking sockets?

2. Do you use threads?

3. Do you parallelise concurrent activity?

4. Do you have large global locks/mutexes?

5. Does your program support SMP?

Quote:
It's easier to improve the performance of a correct program than improve the correctness of a high performing program
 

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ppmtopgm(1)                                                   General Commands Manual                                                  ppmtopgm(1)

NAME
ppmtopgm - convert a portable pixmap into a portable graymap SYNOPSIS
ppmtopgm [ppmfile] DESCRIPTION
Reads a portable pixmap as input. Produces a portable graymap as output. The output is a "black and white" rendering of the original image, as in a black and white photograph. The quantization formula used is .299 r + .587 g + .114 b. Note that although there is a pgmtoppm program, it is not necessary for simple conversions from pgm to ppm , because any ppm program can read pgm (and pbm ) files automatically. pgmtoppm is for colorizing a pgm file. Also, see ppmtorgb3 for a different way of converting color to gray. And ppmdist generates a grayscale image from a color image, but in a way that makes it easy to differentiate the original colors, not necessarily a way that looks like a black and white photograph. QUOTE
Cold-hearted orb that rules the night Removes the colors from our sight Red is gray, and yellow white But we decide which is right And which is a quantization error. SEE ALSO
pgmtoppm(1),ppmtorgb3(1),rgb3toppm(1),ppmdist(1),ppm(5),pgm(5) AUTHOR
Copyright (C) 1989 by Jef Poskanzer. 10 April 2000 ppmtopgm(1)
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