On Thu, Apr 05, 2018 at 09:58:36AM -0600, Warner Losh wrote: > On Thu, Apr 5, 2018 at 9:46 AM, Roger Pau Monné <roy...@freebsd.org> wrote: > > > On Thu, Apr 05, 2018 at 09:32:57AM -0600, Ian Lepore wrote: > > > On Thu, 2018-04-05 at 14:31 +0000, Roger Pau Monné wrote: > > > > Author: royger > > > > Date: Thu Apr 5 14:31:54 2018 > > > > New Revision: 332072 > > > > URL: https://svnweb.freebsd.org/changeset/base/332072 > > > > > > > > Log: > > > > introduce GiB and MiB macros > > > > > > > > This macros convert from GiB or MiB into bytes. > > > > > > > > Sponsored by: Citrix Systems R&D > > > > > > > > Modified: > > > > head/sys/sys/param.h > > > > > > > > Modified: head/sys/sys/param.h > > > > ============================================================ > > ================== > > > > --- head/sys/sys/param.h Thu Apr 5 14:25:39 2018 (r332071) > > > > +++ head/sys/sys/param.h Thu Apr 5 14:31:54 2018 (r332072) > > > > @@ -362,4 +362,8 @@ __END_DECLS > > > > */ > > > > #define __PAST_END(array, offset) (((__typeof__(*(array)) > > *)(array))[offset]) > > > > > > > > +/* Unit conversion macros. */ > > > > +#define GiB(v) (v ## ULL << 30) > > > > +#define MiB(v) (v ## ULL << 20) > > > > + > > > > #endif /* _SYS_PARAM_H_ */ > > > > > > > > > > These names don't make it clear whether the conversion is bytes->GiB or > > > GiB->bytes. The names seem way too generic for a public namespace in a > > > file as heavily included behind your back as param.h is. > > > > > > Also, this completely reasonable usage won't work, likely with > > > confusing compile error messages: > > > > > > int bytes, gibytes; > > > ... > > > bytes = GiB(gibytes); > > > > I find those helpful for their specific usage. I could introduce > > static inline functions like: > > > > size_t gb_to_bytes(size_t)... > > > > But I assume this is also going to cause further discussion. > > > > Yea, traditional macro names would be "gibtob" and "btogib" but I didn't > just reply to bikeshed a name: > > But you don't need to specify a type, consider the current btodb macro: > #define btodb(bytes) /* calculates (bytes / DEV_BSIZE) > */ \ > (sizeof (bytes) > sizeof(long) \ > ? (daddr_t)((unsigned long long)(bytes) >> DEV_BSHIFT) \ > : (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT)) > > which shows how to do this in a macro, which is orthogonal to any name you > may choose. I can also bikeshed function vs macro :)
I was just going to remove those from here and place them in the files where I use them, but I can also change them to: #define gibtob(gib) ((unsigned long long)(gib) << 30) #define mibtob(mib) ((unsigned long long)(mib) << 20) If it's not going to start a bikeshed. Thanks, Roger. _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
