JFFS3 & performance

[jasmine at linuxgrrls.org]

On Fri, 7 Jan 2005, Artem B. Bityuckiy wrote:

>> i)  The instruction cache suffers from this penalty and is, in fact, the
>>     major issue here.  Most of the wasted cycles will be waiting for an
>>     instruction to arrive from the i-cache.

> I'm sorry, not exactly. Ok, could you please write the code you think is
> better? Currentlly it is:

I don't know.  I guess you'd need to use inline assembler to shove the 
code around.  I don't know how to do that in Linux any more, but in the 
OS I'm used to it would look something like this:

/* Trash the CPU data chache */
trash_cache();
ts1 = TIMESTAMP();
asm(ALIGN_32);
for (j = 0; j < memsizes[i]; j++)
 	mem[i][j] = mem[i][j] + 1;
asm(ALIGN_32);
for (j = 0; j < memsizes[i]; j++)
        mem[i][j] = mem[i][j] + 1;
ts2 = TIMESTAMP();