Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752298AbdFZKCK (ORCPT ); Mon, 26 Jun 2017 06:02:10 -0400 Received: from mail-wm0-f42.google.com ([74.125.82.42]:35731 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbdFZJ63 (ORCPT ); Mon, 26 Jun 2017 05:58:29 -0400 From: "=?UTF-8?q?Javier=20Gonz=C3=A1lez?=" X-Google-Original-From: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= To: mb@lightnvm.io, axboe@fb.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= Subject: [PATCH 14/20] lightnvm: pblk: choose optimal victim GC line Date: Mon, 26 Jun 2017 11:57:23 +0200 Message-Id: <1498471049-25505-15-git-send-email-javier@cnexlabs.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498471049-25505-1-git-send-email-javier@cnexlabs.com> References: <1498471049-25505-1-git-send-email-javier@cnexlabs.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1857 Lines: 54 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 Signed-off-by: Matias Bjørling --- drivers/lightnvm/pblk-gc.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) 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 @@ static void pblk_gc_run(struct pblk *pblk) 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); -- 2.7.4