From: Junio C Hamano Date: Tue, 17 Apr 2007 22:00:28 GMT Subject: Re: [PATCH] refs.c: add a function to sort a ref list, rather then sorting on add Message-ID: <7vslaymzk3.fsf@assigned-by-dhcp.cox.net> In-Reply-To: Linus Torvalds writes: > On Tue, 17 Apr 2007, Julian Phillips wrote: >> >> Rather than sorting the refs list while building it, sort in one go >> after it is built using a merge sort. This has a large performance >> boost with large numbers of refs. >> >> Signed-off-by: Julian Phillips > > Acked-by: Linus Torvalds > > Looks fine. I think that even your new times are a bit high (over two > seconds?) but things are clearly better. Have you looked at what takes so > long now? I wonder why the loss of "we are replacing the same one" case in the original add_ref() was not compensated for in the new sort_ref_list(). I think we would not call add_ref() to the same list with duplicate names, unless (1) filesystem is grossly corrupt, (2) somebody added a new ref while we are walking (how does readdir() behave in such a case???), or (3) packed-refs file is corrupt.