Re: [PATCH 1/4] f2fs: avoid very large discard command
From: Christoph Hellwig <hch@infradead.org>
Date: 2017-02-23 10:16:27
Also in:
linux-f2fs-devel, linux-fsdevel, lkml
On Wed, Feb 22, 2017 at 08:28:47PM -0800, Jaegeuk Kim wrote:
This patch adds MAX_DISCARD_BLOCKS() to avoid issuing too much large single discard command.
Needs an explanation in the code on why this number was chosen. In doubt I suspect it should be a quirk in the driver for the device, and not something decided by the fs.
quoted hunk
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> --- fs/f2fs/f2fs.h | 3 ++- fs/f2fs/segment.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index d076b94530bc..5f3fe97df055 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h@@ -133,7 +133,8 @@ enum { (SM_I(sbi)->trim_sections * (sbi)->segs_per_sec) #define BATCHED_TRIM_BLOCKS(sbi) \ (BATCHED_TRIM_SEGMENTS(sbi) << (sbi)->log_blocks_per_seg) - +#define MAX_DISCARD_BLOCKS(sbi) \ + ((1 << (sbi)->log_blocks_per_seg) * (sbi)->segs_per_sec) #define DISCARD_ISSUE_RATE 8 #define DEF_CP_INTERVAL 60 /* 60 secs */ #define DEF_IDLE_INTERVAL 5 /* 5 secs */diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index fe434cd872b4..567019940e9b 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c@@ -886,7 +886,8 @@ static void __add_discard_entry(struct f2fs_sb_info *sbi, if (!list_empty(head)) { last = list_last_entry(head, struct discard_entry, list); if (START_BLOCK(sbi, cpc->trim_start) + start == - last->blkaddr + last->len) { + last->blkaddr + last->len && + last->len < MAX_DISCARD_BLOCKS(sbi)) { last->len += end - start; goto done; }-- 2.11.0
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