Speedup mark_random_map()
authorJens Axboe <jens.axboe@oracle.com>
Mon, 2 Jun 2008 07:53:05 +0000 (09:53 +0200)
committerJens Axboe <jens.axboe@oracle.com>
Mon, 2 Jun 2008 07:53:05 +0000 (09:53 +0200)
Do each int at the time, not each bit.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
io_u.c

diff --git a/io_u.c b/io_u.c
index c662470..f2fa859 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -43,14 +43,14 @@ static void mark_random_map(struct thread_data *td, struct io_u *io_u)
        unsigned int min_bs = td->o.rw_min_bs;
        struct fio_file *f = io_u->file;
        unsigned long long block;
-       unsigned int blocks;
-       unsigned int nr_blocks;
+       unsigned int blocks, nr_blocks;
 
        block = (io_u->offset - f->file_offset) / (unsigned long long) min_bs;
-       blocks = 0;
        nr_blocks = (io_u->buflen + min_bs - 1) / min_bs;
+       blocks = 0;
 
-       while (blocks < nr_blocks) {
+       while (nr_blocks) {
+               unsigned int this_blocks, mask;
                unsigned int idx, bit;
 
                /*
@@ -65,18 +65,27 @@ static void mark_random_map(struct thread_data *td, struct io_u *io_u)
 
                fio_assert(td, idx < f->num_maps);
 
-               f->file_map[idx] |= (1 << bit);
-               block++;
-               blocks++;
+               this_blocks = nr_blocks;
+               if (this_blocks + bit > BLOCKS_PER_MAP)
+                       this_blocks = BLOCKS_PER_MAP - bit;
+
+               if (this_blocks == BLOCKS_PER_MAP)
+                       mask = -1U;
+               else
+                       mask = ((1U << this_blocks) - 1) << bit;
+
+               fio_assert(td, !(f->file_map[idx] & mask));
+               f->file_map[idx] |= mask;
+               nr_blocks -= this_blocks;
+               blocks += this_blocks;
        }
 
        if ((blocks * min_bs) < io_u->buflen)
                io_u->buflen = blocks * min_bs;
 }
 
-static inline unsigned long long last_block(struct thread_data *td,
-                                           struct fio_file *f,
-                                           enum fio_ddir ddir)
+static unsigned long long last_block(struct thread_data *td, struct fio_file *f,
+                                    enum fio_ddir ddir)
 {
        unsigned long long max_blocks;
        unsigned long long max_size;