On Thu, 2015-02-12 at 15:01 -0800, akpm@xxxxxxxxxxxxxxxxxxxx wrote: > From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > Subject: lib/string_helpers.c:string_get_size(): remove redundant prefixes > > While 3c9f3681d0b4 "[SCSI] lib: add generic helper to print sizes rounded > to the correct SI range" says that Z and Y are included in preparation for > 128 bit computers, they just waste .text currently. If and when we get > u128, string_get_size needs updating anyway (and ISO needs to come up with > four more prefixes). This is rubbish. It's nothing to do with 128 bits. This is to do with disk sizes linux gets attached to. The current largest device clusters are Petabytes ... I think we may have some exabyte ones somewhere in the Academic community, so it's by no means inconcievable we'll have Zettabyte ones within a few years. The SCSI standard, with 4k blocks supports up to 2^76, which is well into Zettabytes. We obviously run off the mmap possibilities a lot sooner, because of the byte offsets, but that's fixable. Someone will probably start first by passing blocks into that interface not bytes, so we'd like it not to be based on assumptions that think 2^64 is the largest possible value. > Also there's no need to include and test for the NULL sentinel; once we > reach "E" size is at most 18. [The test is also wrong; it should be > units_str[units][i+1]; if we've reached NULL we're already doomed.] So fix the bug, don't set us up to run off the end of the array. And please consult the community which keeps track of this rather than trying to get it into Linux without review. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
