From: Jeff King Date: Wed, 30 Oct 2013 08:12:01 GMT Subject: Re: [PATCH 12/19] rev-list: add bitmap mode to speed up object lists Message-ID: <20131030081201.GL11317@sigill.intra.peff.net> In-Reply-To: On Fri, Oct 25, 2013 at 02:00:48PM +0000, Shawn O. Pearce wrote: > On Thu, Oct 24, 2013 at 6:06 PM, Jeff King wrote: > > Note that most of the time we spend for --count invocations is on > > generating the pack revindex. It may be worth storing a revidx (either > > in a separate file, as part of the .idx, or as an optional section in > > the .bitmap file). > > This was discussed before, and it may make sense to cache the revidx. > I'm glad to see the timings are already better with bitmaps, even > though the revidx has to be computed on the fly for each invocation. The radix sort makes a _huge_ difference there. But I would still like an mmap-able .revidx cache. I think we can get at least another order-of-magnitude speedup. I'm intentionally leaving that out for now, though. I want to get this series merged before trying to go much further. -Peff