Messages in this thread | | | Date | Fri, 16 Jul 2021 10:05:13 -0700 | From | Yury Norov <> | Subject | Re: [PATCH 2/2] bitmap: introduce for_each_set_bitrange |
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On Fri, Jul 16, 2021 at 03:46:43PM +0200, Petr Mladek wrote: > On Thu 2021-07-15 08:50:21, Yury Norov wrote: > > On Fri, Jul 09, 2021 at 09:59:50AM -0400, Steven Rostedt wrote: > > > On Thu, 8 Jul 2021 20:45:19 -0700 > > > Yury Norov <yury.norov@gmail.com> wrote: > > > > > > > bitmap_list_string() is very ineffective when printing bitmaps with long > > > > ranges of set bits because it calls find_next_bit for each bit. We can do > > > > better by detecting ranges of set bits. > > > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > > > > index 87acf66f0e4c..1ee54dace71e 100644 > > > > --- a/lib/vsprintf.c > > > > +++ b/lib/vsprintf.c > > > > > > > > - buf = number(buf, end, rtop, default_dec_spec); > > > > - } > > > > + if (buf > start) > > > > + buf--; > > > > > > If the above is to undo the last comma, please put back the first logic. > > > > You're asking me to move part of the logic inside the loop which generally > > should be avoided. Is there any particular reason to do this? > > vsprintf() should write what is needed and keep the rest of the given > buffer intact. There is even a test for this in the test_printf module. > > I think that test_printf does not complain here because only a single > character is used and it is later replaced by the trailing '\0'. > > By other words, undoing the last comma does not cause visible problems > in the end. But from vsprintf() point of view, it is a hack that does > not trigger the warning only by chance. And it is better to avoid it. > > Best Regards, > Petr
Ah, OK. Thanks Petr.
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