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authorJavier González <jg@lightnvm.io>2017-06-26 12:57:23 +0300
committerJens Axboe <axboe@kernel.dk>2017-06-27 01:27:39 +0300
commitd45ebd470bb6d41eb5294733bdba78a7ad69f1d0 (patch)
tree895ebef437c4325bdcf61011f14bc961ce1bc78e
parentdffdd960ee16d0515d32701301760a817a25d52b (diff)
downloadlinux-d45ebd470bb6d41eb5294733bdba78a7ad69f1d0.tar.xz
lightnvm: pblk: choose optimal victim GC line
At the moment, we separate the closed lines on three different list based on their number of valid sectors. GC recycles lines from each list based on capacity. Lines from each list are taken in a FIFO fashion. Since the number of lines is limited (it corresponds to the number of blocks in a LUN, which is somewhere between 1000-2000), we can afford scanning the lists to choose the optimal line to be recycled. This helps specially in lines with a high number of valid sectors. If the number of blocks per LUN increases, we will consider a more efficient policy. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/lightnvm/pblk-gc.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 2e7fb7a51854..f811e4ca63f4 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -287,6 +287,20 @@ static void pblk_gc_lines(struct pblk *pblk, struct list_head *gc_list)
}
}
+static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
+ struct list_head *group_list)
+{
+ struct pblk_line *line, *victim;
+
+ victim = list_first_entry(group_list, struct pblk_line, list);
+ list_for_each_entry(line, group_list, list) {
+ if (*line->vsc < *victim->vsc)
+ victim = line;
+ }
+
+ return victim;
+}
+
/*
* Lines with no valid sectors will be returned to the free list immediately. If
* GC is activated - either because the free block count is under the determined
@@ -332,7 +346,7 @@ next_gc_group:
return;
}
- line = list_first_entry(group_list, struct pblk_line, list);
+ line = pblk_gc_get_victim_line(pblk, group_list);
nr_blocks_free += atomic_read(&line->blk_in_line);
spin_lock(&line->lock);