On Wed, 22 May 2019 13:25:50 +0200 Boris Brezillon <[email protected]> wrote:
> Some users might need extra context to compare 2 elements. This patch > adds the sort_r() which is similar to the qsort_r() variant of qsort(). > > Signed-off-by: Boris Brezillon <[email protected]> > --- > Hello, > > A few more details about this patch. > > Even though I post it as a standalone patch, I do intend to use it in > a real driver (v4l2 driver), just didn't want to have it burried in a > huge patch series. > > Note that sort() and sort_r() are now implemented as wrappers around > do_sort() so that most of the code can be shared. I initially went for > a solution that implemented sort() as a wrapper around sort_r() (which > basically contained the do_sort() logic without the cmp_func arg) > but realized this was adding one extra indirect call (the compare func > wrapper), which I know are being chased. Please move the above text into the changelog. It's probably useful and we can afford the disk space ;) > There's another option, but I'm pretty sure other people already > considered it and thought it was not a good idea as it would make > the code size grow: move the code to sort.h as inline funcs/macros so > that the compiler can optimize things out and replace the indirect > cmp_func() calls by direct ones. I just tried it, and it makes my .o > file grow by 576 bytes, given that we currently have 122 users of > this function, that makes the kernel code grow by ~70k (that's kind > of a max estimate since not all users will be compiled in). eep, let's not do that. > --- a/include/linux/sort.h > +++ b/include/linux/sort.h Patch otherwise looks OK. Please include it with the patch series which uses it. Feel free to add Acked-by: Andrew Morton <[email protected]>
