From: Linus Torvalds Date: Fri, 16 Sep 2005 21:32:48 +0000 (-0700) Subject: [PATCH] Improve git-rev-list memory usage further X-Git-Tag: v0.99.7~19 X-Git-Url: https://git.octo.it/?a=commitdiff_plain;h=b0d8923ec01fd91b75ab079034f89ced91500157;p=git.git [PATCH] Improve git-rev-list memory usage further This avoids keeping tree entries around, and free's them as it traverses the list. This avoids building up a huge memory footprint just for these small but very common allocations. Before: $ /usr/bin/time git-rev-list --objects v2.6.12..HEAD | wc -l 11.65user 0.38system 0:12.65elapsed 95%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+42934minor)pagefaults 0swaps 59124 After: $ /usr/bin/time git-rev-list --objects v2.6.12..HEAD | wc -l 12.28user 0.29system 0:12.57elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+26718minor)pagefaults 0swaps 59124 Note how the minor fault numbers - which ends up being how many pages we needed to map - go down from 42934 (167 MB) to 26718 (104 MB). That is: Before: 42934 minor pagefaults After: 26718 minor pagefaults This is all in _addition_ to the previous fixes. It used to be ~48,000 pagefaults. That's still a honking big memory footprint, but it's about half of what it was just a day or two ago (and this is the object list for a pretty big update - almost 60,000 objects. Smaller updates need less memory). Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- diff --git a/rev-list.c b/rev-list.c index c410bc33..91534dd2 100644 --- a/rev-list.c +++ b/rev-list.c @@ -147,11 +147,16 @@ static struct object_list **process_tree(struct tree *tree, struct object_list * die("bad tree object %s", sha1_to_hex(obj->sha1)); obj->flags |= SEEN; p = add_object(obj, p, name); - for (entry = tree->entries ; entry ; entry = entry->next) { + entry = tree->entries; + tree->entries = NULL; + while (entry) { + struct tree_entry_list *next = entry->next; if (entry->directory) p = process_tree(entry->item.tree, p, entry->name); else p = process_blob(entry->item.blob, p, entry->name); + free(entry); + entry = next; } return p; } @@ -218,12 +223,15 @@ static void mark_tree_uninteresting(struct tree *tree) if (parse_tree(tree) < 0) die("bad tree %s", sha1_to_hex(obj->sha1)); entry = tree->entries; + tree->entries = NULL; while (entry) { + struct tree_entry_list *next = entry->next; if (entry->directory) mark_tree_uninteresting(entry->item.tree); else mark_blob_uninteresting(entry->item.blob); - entry = entry->next; + free(entry); + entry = next; } }