Russ Dill wrote:
I've been having a back and forth going for a while with my TA and OS
professor on the meaning of profile=3 and have been unable to convince
either of them. The basic question is if profile=3 is passed to kernel
with an 8MB text section, how big is the allocated profile buffer. His
answer is 1MB....
if (prof_shift) {
unsigned int size;
/* only text is profiled */
prof_len = (unsigned *) &_etext - (unsigned *) &_stext;
You stipulated 8MB text, but this calculates in unsigned ints, so
prof_len = 2M.
prof_len >>= prof_shift;
This gives 250K (divide by 8).
size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1;
Finally, size is 1MB (250K x 4).
prof_buffer = (unsigned int *) alloc_bootmem(size);
}
I'm with your Prof. Perhaps you missed that prof_len counts integers,
not bytes.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
