Re: [PATCH] fetch-pack: grow stateless RPC windows exponentially
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 18, 2016, 20:00 UTC
- Message-ID
- <xmqqoa5uiumu.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <20160718193147.GC29326@google.com>
Jonathan Nieder <jrnieder@gmail.com> writes:
Show 29 quoted lines
> You have full control of the growth function. So how about aggressive > growth until 1024*10? > > That is: > > Current git: > n < 1024: aggressive exponential > 16, 32, 64, 128, 256, 512, 1024 > 1024 <= n: linear > 2048, 3072, 4096, 5120, ... > > Initial proposal: > n < 1024: aggressive exponential > 16, 32, 64, 128, 256, 512, 1024 > 1024 <= n < 10240: linear > 2048, 307, 4096, 5120, ... > 10240 <= n: conservative exponential > 11264, 12390, ... > > New proposal: > n < 10240: aggressive exponential > 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384 > 10240 <= n: conservative exponential > 18022, 19824, ... > > That way, on one hand it would still never use a smaller window than > today and on the other hand the heuristic would be easier to > understand (only decelarating, instead of decelarating and then > accelerating again).
That sounds more explainable (I do not know if that is a growth curve that gives us better results, though).
So, the result would look something like this, perhaps?
fetch-pack.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/fetch-pack.c b/fetch-pack.c index 3c5dfc4..97fe5f7 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -264,12 +264,17 @@ static void insert_one_alternate_ref(const struct ref *ref, void *unused) static int next_flush(struct fetch_pack_args *args, int count) { - int flush_limit = args->stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH; - - if (count < flush_limit) - count <<= 1; - else - count += flush_limit; + if (args->stateless_rpc) { + if (count < LARGE_FLUSH * 10) + count <<= 1; + else + count = count * 11 / 10; + } else { + if (count < PIPESAFE_FLUSH) + count <<= 1; + else + count += PIPESAFE_FLUSH; + } return count; }