mirror of https://github.com/vitalif/e2fsprogs
libext2fs: further optimize rb_test_bit
Profiling shows that rb_test_bit() is now calling ext2fs_rb_next() a lot, and this function is now the hot spot when running e2freefrag. If we cache the results of ext2fs_rb_next(), we can eliminate those extra calls, which further speeds up both e2freefrag and e2fsck by reducing the amount of CPU time spent in userspace. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>bitmap-optimize
parent
0bcba36f3f
commit
fb129bba73
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@ -40,6 +40,7 @@ struct ext2fs_rb_private {
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struct rb_root root;
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struct bmap_rb_extent *wcursor;
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struct bmap_rb_extent *rcursor;
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struct bmap_rb_extent *rcursor_next;
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#ifdef BMAP_STATS_OPS
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__u64 mark_hit;
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__u64 test_hit;
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@ -152,6 +153,8 @@ static void rb_free_extent(struct ext2fs_rb_private *bp,
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bp->wcursor = NULL;
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if (bp->rcursor == ext)
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bp->rcursor = NULL;
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if (bp->rcursor_next == ext)
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bp->rcursor_next = NULL;
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ext2fs_free_mem(&ext);
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}
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@ -166,6 +169,7 @@ static errcode_t rb_alloc_private_data (ext2fs_generic_bitmap bitmap)
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bp->root = RB_ROOT;
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bp->rcursor = NULL;
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bp->rcursor_next = NULL;
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bp->wcursor = NULL;
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#ifdef BMAP_STATS_OPS
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@ -306,7 +310,7 @@ static errcode_t rb_resize_bmap(ext2fs_generic_bitmap bmap,
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inline static int
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rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
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{
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struct bmap_rb_extent *rcursor, *next_ext;
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struct bmap_rb_extent *rcursor, *next_ext = NULL;
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struct rb_node *parent = NULL, *next;
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struct rb_node **n = &bp->root.rb_node;
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struct bmap_rb_extent *ext;
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@ -322,9 +326,15 @@ rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
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return 1;
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}
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next = ext2fs_rb_next(&rcursor->node);
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if (next) {
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next_ext = ext2fs_rb_entry(next, struct bmap_rb_extent, node);
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next_ext = bp->rcursor_next;
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if (!next_ext) {
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next = ext2fs_rb_next(&rcursor->node);
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if (next)
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next_ext = ext2fs_rb_entry(next, struct bmap_rb_extent,
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node);
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bp->rcursor_next = next_ext;
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}
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if (next_ext) {
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if ((bit >= rcursor->start + rcursor->count) &&
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(bit < next_ext->start)) {
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#ifdef BMAP_STATS_OPS
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@ -333,6 +343,8 @@ rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
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return 0;
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}
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}
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bp->rcursor = NULL;
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bp->rcursor_next = NULL;
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rcursor = bp->wcursor;
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if (!rcursor)
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@ -352,6 +364,7 @@ search_tree:
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n = &(*n)->rb_right;
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else {
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bp->rcursor = ext;
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bp->rcursor_next = NULL;
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return 1;
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}
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}
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@ -368,6 +381,7 @@ static int rb_insert_extent(__u64 start, __u64 count,
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struct bmap_rb_extent *ext;
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int retval = 0;
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bp->rcursor_next = NULL;
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ext = bp->wcursor;
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if (ext) {
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if (start >= ext->start &&
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@ -738,6 +752,7 @@ static void rb_clear_bmap(ext2fs_generic_bitmap bitmap)
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rb_free_tree(&bp->root);
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bp->rcursor = NULL;
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bp->rcursor_next = NULL;
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bp->wcursor = NULL;
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}
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