On Tue, Mar 10, 2015 at 05:48:37PM +0100, Arnd Bergmann wrote: > The cfi_staa_write_buffers function uses a large amount of kernel stack > whenever CONFIG_MTD_MAP_BANK_WIDTH_32 is set, and that results in a > warning on ARM allmodconfig builds: > > drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_write_buffers': > drivers/mtd/chips/cfi_cmdset_0020.c:651:1: warning: the frame size of 1208 > bytes is larger than 1024 bytes [-Wframe-larger-than=] > > It turns out that this is largely a result of a suboptimal implementation > of map_word_andequal(). Replacing this function with a straightforward > one reduces the stack size in this function by exactly 200 bytes, > shrinks the .text segment for this file from 27648 bytes to 26608 bytes, > and makes the warning go away.
Patch looks OK to me, and those results are nice. Did you (or anyone else) do any testing? > Signed-off-by: Arnd Bergmann <[email protected]> > --- > v3: more whitespace changes > v2: whitespace changes > > diff --git a/include/linux/mtd/map.h b/include/linux/mtd/map.h > index 47c59991491b..29975c73a953 100644 > --- a/include/linux/mtd/map.h > +++ b/include/linux/mtd/map.h > @@ -316,7 +316,17 @@ static inline map_word map_word_or(struct map_info *map, > map_word val1, map_word > return r; > } > > -#define map_word_andequal(m, a, b, z) map_word_equal(m, z, map_word_and(m, > a, b)) > +static inline int map_word_andequal(struct map_info *map, map_word val1, > map_word val2, map_word val3) > +{ > + int i; > + > + for (i = 0; i < map_words(map); i++) { > + if ((val1.x[i] & val2.x[i]) != val3.x[i]) > + return 0; > + } > + > + return 1; > +} > > static inline int map_word_bitsset(struct map_info *map, map_word val1, > map_word val2) > { > -- 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/
