Re: [PATCH] speedup allocation in pack-redundant.c
- From
Lukas Sandström <lukass@etek.chalmers.se>
- Date
- Nov 22, 2005, 23:55 UTC
- Message-ID
- <4383AFDB.90907@etek.chalmers.se>
- In-Reply-To
- <20051122233845.GC2916@steel.home>
Alex Riesen wrote:
Show 17 quoted lines
> Lukas Sandström, Wed, Nov 23, 2005 00:14:53 +0100: > >>>>I think making allocation/deallocation to the central place is a >>>>good cleanup, but I am not sure about the free-nodes reusing. >>>>Does this make difference in real life? >>> >>>It definitely does, though nor very much. I have no real numbers at >>>hand (being home now), but I remember it was 1 min with against 3 min >>>without the patch on cygwin+fat32, which is already bad enough all by >>>itself. Very big repository with no redundant packs in it. >> >>Would you mind sharing the .idx files? > > > this time I probably would (they're not here)... But for a perfomance > testing any big repository will do, linux kernel, for example. >
The problem is that the large repository I have contains lots of redundant packs, which makes quite fast to find a complete set and end the search. If you don't have any redundant packs, the complete set search really is 2**n (n = the number of packs).
I did some quick experiments with slab allocation and got a 4.4% improvement on the redundant repo, so that might be worth persuing. (Concept patch below)
diff --git a/pack-redundant.c b/pack-redundant.c index b38baa9..05294f8 100644 --- a/pack-redundant.c +++ b/pack-redundant.c @@ -8,6 +8,8 @@ #include "cache.h" +#define BLKSIZE 1024 + static const char pack_redundant_usage[] = "git-pack-redundant [ --verbose ] [ --alt-odb ] < --all | <.pack filename> ...>"; @@ -38,24 +40,28 @@ struct pll { static struct llist_item *free_nodes = NULL; +static inline void llist_item_put(struct llist_item *item) +{ + item->next = free_nodes; + free_nodes = item; +} + static inline struct llist_item *llist_item_get() { struct llist_item *new; if ( free_nodes ) { new = free_nodes; free_nodes = free_nodes->next; - } else - new = xmalloc(sizeof(struct llist_item)); - + } else { + int i = 1; + new = xmalloc(sizeof(struct llist_item) * BLKSIZE); + for(;i < BLKSIZE; i++) { + llist_item_put(&new[i]); + } + } return new; } -static inline void llist_item_put(struct llist_item *item) -{ - item->next = free_nodes; - free_nodes = item; -} - static void llist_free(struct llist *list) { while((list->back = list->front)) {