On Thu, Dec 21 2006, Seetharami Seelam wrote: > On 12/21/06, Jens Axboe <[EMAIL PROTECTED]> wrote: > > > >On Thu, Dec 21 2006, Ming Zhang wrote: > >> On Thu, 2006-12-21 at 08:42 +0100, Jens Axboe wrote: > >> > On Wed, Dec 20 2006, Ming Zhang wrote: > >> > > On Wed, 2006-12-20 at 14:09 -0600, Seetharami Seelam wrote: > >> > > > > >> > > > On 12/20/06, Ming Zhang <[EMAIL PROTECTED]> wrote: > >> > > > On Wed, 2006-12-20 at 17:45 +0100, Jens Axboe wrote: > >> > > > > On Wed, Dec 20 2006, Ming Zhang wrote: > >> > > > > > > >> > > > > > On Wed, 2006-12-20 at 14:02 +0100, Jens Axboe wrote: > >> > > > > > > On Wed, Dec 20 2006, Jens Axboe wrote: > >> > > > > > > > On Wed, Dec 20 2006, Jens Axboe wrote: > >> > > > > > > > > Irk, do_pipe() needs to know what the input is, > >> > > > obviously. Lemme add > >> > > > > > > > > that as well. > >> > > > > > > > > >> > > > > > > > This has a better chance of working, still not > >tested > >> > > > though. If you can > >> > > > > > > > test, I'll commit it once we have it working. > >> > > > > > > > >> > > > > > > It works for me, just tested it. Patch committed. > >> > > > > > > > >> > > > > > > >> > > > > > yes, works. thx. > >> > > > > > > >> > > > > > now the fifo will use a name pattern like foo. but > >regular > >> > > > file will use > >> > > > > > foo.blktrace.X and if you give full name, blkparse > >does > >> > > > not report any > >> > > > > > warning or error, just return 0 results. this drove me > >> > > > nuts before i > >> > > > > > read the code. > >> > > > > > > >> > > > > > [ [EMAIL PROTECTED] blktrace]$ ./blkparse a.a.blktrace.0 > >> > > > > > WARNING: full file name given. Should give trace name > >foo, > >> > > > > > instead of file name foo.blktrace.x > >> > > > > > >> > > > > Better would be to just fix it up for the user, the > >current > >> > > > setup is a > >> > > > > little un-intuitive. Care to patch that up? :-) > >> > > > > > >> > > > > >> > > > are these what u want? > >> > > > > >> > > > * user supplied a foo, we automatically match it with > >> > > > foo.blktrace.X and > >> > > > open. > >> > > > * user supplied a foo.blktrace.X, we do not add extra > >> > > > blktace.X and open > >> > > > it directly. > >> > > > > >> > > > then if user have foo.blktrace.0 and foo.blktrace.1, > >current > >> > > > code works > >> > > > when use "-i foo". then shall we support "-i > >foo.blktrace.0" > >> > > > and open > >> > > > foo.blktrace.1 automatically? > >> > > > > >> > > > > >> > > > Perhaps, if user explicity supplies the name(s), you > >should > >> > > > open just that (those) file(s). May be you should open all > >> > > > when the name is supplied as foo.blktrace.* > >> > > > >> > > key point here is not the implementation difficulty, but how we > >decide a > >> > > consistent rule. i agree with the rules u set, if i understand > >> > > correctly. > >> > > > >> > > * if "-", then read from stdin; > >> > > * if file name is foo.blktrace.*, then we try to open all; > >> > > * all other file name pattern, we open only _one_ file with _exact_ > >file > >> > > name. > >> > > > >> > > See if others like this. > >> > > >> > I think that is the best approach, if the case where the full name is > >> > given we check and warn if other CPU files are there. It could just be > >a > >> > pilot error, and we should warn in that case. > >> > > >> > "You specified file foo.blktrace.0 and files from other CPUs also > >exist. > >> > blkparse will only read the given file, which may not be what you > >want. > >> > Use 'foo' as the filename to read all saved data." > >> > > >> > or something to that effect. > >> > >> ok. i will give it a try. > > > >On 2nd thought, is it _ever_ a good idea not to read all the files? The > >message will whiz by and nobody will ever see it, they will just get > >partial (and bad) data. So probably that case of giving foo.blktrace.x > >should just work like doing foo. > > > Not necessarily bad data. When you are playing with HT on/off or adding and > removing processors, and if you accidentally use the same name foo this will > be useful.
That's really an obscure scenario though, I'd consider it many times more likely that someone will acidentally give a full file name than someone rerunning the same trace with less CPUs. It's a lot better to prevent accidental problems imho. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
