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From: colyli@suse.de
To: axboe@kernel.dk
Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org,
	Coly Li <colyli@suse.de>,
	stable@vger.kernel.org
Subject: [PATCH 14/17] bcache: back to cache all readahead I/Os
Date: Fri, 24 Jan 2020 01:01:39 +0800	[thread overview]
Message-ID: <20200123170142.98974-15-colyli@suse.de> (raw)
In-Reply-To: <20200123170142.98974-1-colyli@suse.de>

From: Coly Li <colyli@suse.de>

In year 2007 high performance SSD was still expensive, in order to
save more space for real workload or meta data, the readahead I/Os
for non-meta data was bypassed and not cached on SSD.

In now days, SSD price drops a lot and people can find larger size
SSD with more comfortable price. It is unncessary to bypass normal
readahead I/Os to save SSD space for now.

This patch removes the code which checks REQ_RAHEAD tag of bio in
check_should_bypass(), then all readahead I/Os will be cached on SSD.

NOTE: this patch still keeps the checking of "REQ_META|REQ_PRIO" in
should_writeback(), because we still want to cache meta data I/Os
even they are asynchronized.

Cc: stable@vger.kernel.org
Signed-off-by: Coly Li <colyli@suse.de>
Acked-by: Eric Wheeler <bcache@linux.ewheeler.net>
---
 drivers/md/bcache/request.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 73478a91a342..acc07c4f27ae 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -378,15 +378,6 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 	     op_is_write(bio_op(bio))))
 		goto skip;
 
-	/*
-	 * Flag for bypass if the IO is for read-ahead or background,
-	 * unless the read-ahead request is for metadata
-	 * (eg, for gfs2 or xfs).
-	 */
-	if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) &&
-	    !(bio->bi_opf & (REQ_META|REQ_PRIO)))
-		goto skip;
-
 	if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
 	    bio_sectors(bio) & (c->sb.block_size - 1)) {
 		pr_debug("skipping unaligned io");
-- 
2.16.4

  parent reply	other threads:[~2020-01-23 17:01 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 17:01 [PATCH 00/17] bcache patches for Linux v5.6 colyli
2020-01-23 17:01 ` [PATCH 01/17] bcache: cached_dev_free needs to put the sb page colyli
2020-01-23 17:01 ` [PATCH 02/17] bcache: use a separate data structure for the on-disk super block colyli
2020-01-23 17:01 ` [PATCH 03/17] bcache: rework error unwinding in register_bcache colyli
2020-01-23 17:01 ` [PATCH 04/17] bcache: properly initialize 'path' and 'err' in register_bcache() colyli
2020-01-23 17:01 ` [PATCH 05/17] bcache: fix use-after-free " colyli
2020-01-23 17:01 ` [PATCH 06/17] bcache: transfer the sb_page reference to register_{bdev,cache} colyli
2020-01-23 17:01 ` [PATCH 07/17] bcache: return a pointer to the on-disk sb from read_super colyli
2020-01-23 17:01 ` [PATCH 08/17] bcache: store a pointer to the on-disk sb in the cache and cached_dev structures colyli
2020-01-23 17:01 ` [PATCH 09/17] bcache: use read_cache_page_gfp to read the superblock colyli
2020-01-23 17:01 ` [PATCH 10/17] lib: crc64: include <linux/crc64.h> for 'crc64_be' colyli
2020-01-23 17:01 ` [PATCH 11/17] bcache: add code comments for state->pool in __btree_sort() colyli
2020-01-23 17:01 ` [PATCH 12/17] bcache: avoid unnecessary btree nodes flushing in btree_flush_write() colyli
2020-01-23 17:01 ` [PATCH 13/17] bcache: print written and keys in trace_bcache_btree_write colyli
2020-01-23 17:01 ` colyli [this message]
2020-01-23 17:19   ` [PATCH 14/17] bcache: back to cache all readahead I/Os Michael Lyle
2020-01-23 17:27     ` Coly Li
2020-01-23 18:31       ` Jens Axboe
2020-01-24  0:49         ` Coly Li
2020-01-24  1:14           ` Jens Axboe
2020-01-24 16:48       ` Michael Lyle
2020-01-23 17:01 ` [PATCH 15/17] bcache: remove member accessed from struct btree colyli
2020-01-23 17:01 ` [PATCH 16/17] bcache: reap c->btree_cache_freeable from the tail in bch_mca_scan() colyli
2020-01-23 17:01 ` [PATCH 17/17] bcache: reap from tail of c->btree_cache " colyli

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