07-03-2012
Why is read-ahead a problem since above is only a 512bytes read, all it takes is normally positioning the drive head .. Then if the cache is the reason, it should affect the file as well, but I am getting the same result for all reps?
More importantly, my experiment is really about time/vs blocksize, and I am trying to make it more accurate :
- Shall I only use regular files?
- position the disk head somewhere else after each test?
- is it possible to flush all caches programmatically ?
Sorry for all those questions ..
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MAKE(1) General Commands Manual MAKE(1)
NAME
make - a program for maintaining large programs
SYNOPSIS
make [-f file] [-iknpqrst] [option] ... [target]
OPTIONS
-f Use file as the makefile
-i Ignore status returned by commands
-k On error, skip to next command
-n Report, but do not execute
-p Print macros and targets
-q Question up-to-dateness of target
-r Rule inhibit; do not use default rules
-s Silent mode
-t Touch files instead of making them
EXAMPLES
make kernel # Make kernel up to date
make -n -f mfile # Tell what needs to be done
DESCRIPTION
Make is a program that is normally used for developing large programs consisting of multiple files. It keeps track of which object files
depend on which source and header files. When called, it does the minimum amount of recompilation to bring the target file up to date.
The file dependencies are expected in makefile or Makefile , unless another file is specified with -f. Make has some default rules built
in, for example, it knows how to make .s files from .c files. Here is a sample makefile .
d=/user/ast # d is a macro
program: head.s tail.s# program depends on these
cc -o program head.s tail.s# tells how to make program
echo Program done. # announce completion
head.s: $d/def.h head.c # head.s depends on these
tail.s: $d/var.h tail.c # tail.s depends on these
A complete description of make would require too much space here. Many books on UNIX discuss make . Study the numerous Makefiles in the
MINIX source tree for examples.
SEE ALSO
cc(1).
MAKE(1)