On 2017/1/10 上午2:34, Kai Krakow wrote: > When compiling kernel 4.9.1, I'm seeing the following warnings: > > In file included from ./include/linux/bio.h:23:0, > from drivers/md/bcache/bcache.h:181, > from drivers/md/bcache/writeback.c:9: > drivers/md/bcache/writeback.c: In Funktion »bch_cached_dev_writeback_init«: > ./include/linux/ioprio.h:15:73: Warnung: Klammern um Arithmetik in Operand von »|« empfohlen [-Wparentheses] > #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) > ^ > drivers/md/bcache/writeback.c:515:25: Anmerkung: bei Substitution des Makros »IOPRIO_PRIO_VALUE« > dc->ioprio_bypass = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NR-1); > ^ > > It suggests to put parentheses around the expression with the "|" > operand. No other kernel source files show warnings for me, so maybe it > should be fixed. > > I would create a patch myself but I'm not sure if it would be correct > and sufficient to put parenthesis around "data" like this: > > #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | (data)) > Hi Kai Krakow, This fix is necessary, please send a patch to IOPRIO_PRIO_VALUE(). BTW, I don't see dc->ioprio_bypass from upstream kernel source, is it from a development tree ? -- Coly Li -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
