Re: [PATCH] Compile failure fix for ppc on 2.6.17-rc4-mm3 (2nd attempt)

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 #define push_end(res, size) do { unsigned long __sz = (size) ; \
-	res->end = ((res->end + __sz) / (__sz + 1)) * (__sz + 1) + __sz; \
+	resource_size_t farEnd = (res->end + __sz); \
+	do_div(farEnd, (__sz + 1)); \
+	res->end = farEnd * (__sz + 1) + __sz; \
     } while (0)

Size here is a) a misnomer (size + 1 is the actual size) and b) always a power
of two minus one.  So instead, do

#define push_end(res, mask) res->end = -(-res->end & ~(unsigned long)mask)

(with a do { } while(0) armour if you prefer).


It's not doing the same as the old code so is your suggested fix a correct replacement?

For example, given 0xfff for size the current code rounds res->end to the next 0x1000 boundary and adds 0xfff. Your propose fix just rounds it to the next 0x1000 if I'm reading it correctly but is what the code was meant to do in the first place? Using masks, the equivilant of the current code is something like;

#define push_end(res, mask) do { \
	res->end = -(-res->end & ~(unsigned long)mask); \
	res->end += mask; \
} while (0)

Yeah forgot a bit, this looks fine.


Segher

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