On Fri, 2019-08-30 at 23:22 +0000, Tim.Bird@xxxxxxxx wrote: > > -----Original Message----- > > From: Brendan Higgins > > > > On Fri, Aug 30, 2019 at 3:46 PM Joe Perches <joe@xxxxxxxxxxx> wrote: > > > On Fri, 2019-08-30 at 21:58 +0000, Tim.Bird@xxxxxxxx wrote: > > > > > From: Joe Perches > > > [] > > > > IMHO %pV should be avoided if possible. Just because people are > > > > doing it doesn't mean it should be used when it is not necessary. > > > > > > Well, as the guy that created %pV, I of course > > > have a different opinion. > > > > > > > > then wouldn't it be easier to pass in the > > > > > > kernel level as a separate parameter and then strip off all printk > > > > > > headers like this: > > > > > > > > > > Depends on whether or not you care for overall > > > > > object size. Consolidated formats with the > > > > > embedded KERN_<LEVEL> like suggested are smaller > > > > > overall object size. > > > > > > > > This is an argument I can agree with. I'm generally in favor of > > > > things that lessen kernel size creep. :-) > > > > > > As am I. > > > > Sorry, to be clear, we are talking about the object size penalty due > > to adding a single parameter to a function. Is that right? > > Not exactly. The argument is that pre-pending the different KERN_LEVEL > strings onto format strings can result in several versions of nearly identical strings > being compiled into the object file. By parameterizing this (that is, adding > '%s' into the format string, and putting the level into the string as an argument), > it prevents this duplication of format strings. > > I haven't seen the data on duplication of format strings, and how much this > affects it, but little things can add up. Whether it matters in this case depends > on whether the format strings that kunit uses are also used elsewhere in the kernel, > and whether these same format strings are used with multiple kernel message levels. deduplication can matter as well, but so far there is little content with kunit_(err|warn|info(=) kunit/example-test.c: kunit_info(test, "initializing\n"); kunit/test.c: kunit_err(test, kunit/test.c: kunit_err(test, "%s", fragment->fragment); kunit/test.c: kunit_err(test, "\n"); kunit/test.c: kunit_err(test, "%s", buf); kunit/test.c: kunit_err(test, "failed to initialize: %d\n", ret); kunit/test.c: kunit_err(test, "test case timed out\n"); kunit/test.c: kunit_err(test, "internal error occurred preventing test case from running: %d\n", kunit/try-catch.c: kunit_err(test, "try timed out\n"); kunit/try-catch.c: kunit_err(test, "wake_up_process() was never called\n"); kunit/try-catch.c: kunit_err(test, "Unknown error: %d\n", exit_code); Of these, only two do match other kernel uses. "initializing\n", "failed to initialize: %d\n"
