[Yaffs] Re: PATCH!!! PATCH!!! (Was Sorry state of YAFFS2)
Sergey Kubushyn
ksi at koi8.net
Sat Oct 15 03:20:33 BST 2005
On Fri, 14 Oct 2005, Sergey Kubushyn wrote:
> On Fri, 14 Oct 2005, Charles Manning wrote:
[dd]
> I do, really _DO_ hope to see it applied and that "Fix your MTD" mantra
> thrown
> away forever. You better start fixing bugs in your wonderFS. I'd
> suggest to
> start from explaining why 36 Mbyte tar takes 51 Mbytes on YAFFS2 FS.
> And
> here is a hint - without that included patch it took 56 Mbytes. If it's
> too
> complex for you, try to look for any illegal cast usage on irregular
> data
> structures. I'm sending you a small program that illustrates the point
> of
> data alignment, you can compile and run it to see yourself how it makes
> a
> surprise even on ix86...
Here is a small demo... Almost helloworld, heh?
=== Cut ===
#include <stdio.h>
#include <stdlib.h>
typedef struct {
int a;
int b;
char c;
int d;
} test;
typedef union {
test t;
char as_char[16];
} u_test;
int main(int argc, char **argv)
{
int i;
/* Another test - remove "static" and see what happens. Why? */
static u_test dummy;
printf("Size of union = %d\n", sizeof(u_test));
printf("Size of structure = %d\n", sizeof(dummy.t));
printf("Total size of structure members = %d. Surprise?\n",
sizeof(dummy.t.a) + sizeof(dummy.t.b) +
sizeof(dummy.t.c) + sizeof(dummy.t.d));
dummy.t.a = 0x12343412;
dummy.t.b = 0x45676745;
dummy.t.c = 0x11;
dummy.t.d = 0x71176556;
for (i = 0; i < 16; i++) {
printf("Char #%d = 0x%02x\n", i, dummy.as_char[i]);
}
return 0;
}
=== Cut ===
---
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