Messages in this thread | | | Subject | RE: Re: [f2fs-dev] [PATCH] f2fs: change write_hint for hot/warm nodes | From | Daejun Park <> | Date | Tue, 03 Nov 2020 17:33:06 +0900 |
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>>>From 818a76a9aee5bf225565264274d211edb07bae7d Mon Sep 17 00:00:00 2001 >> From: Daejun Park <daejun7.park@samsung.com> >> Date: Tue, 3 Nov 2020 15:30:26 +0900 >> >> >> In the fs-based mode of F2FS, the mapping of hot/warm node to >> WRITE_LIFE_NOT_SET should be changed to WRITE_LIFE_SHORT. >> >> As a result of analyzing the write pattern of f2fs using real workload, >> hot/warm nodes have high update ratio close to hot data.[*] >> However, F2FS passes write hints for hot/warm nodes as WRITE_LIFE_NOT_SET. >> >> Furthermore, WRITE_LIFE_NOT_SET is a default value of write hint when it is >> not provided from the file system. >> In storage, write_hint is used to distinguish streams (e.g. NVMe). >> So, the hot/warm node of F2FS is not distinguished from other write_hints, >> which can make the wrong stream seperation. >> >> * Liang, Yu, et al. "An empirical study of F2FS on mobile devices." 2017 >> IEEE 23rd International Conference on Embedded and Real-Time Computing >> Systems and Applications (RTCSA). > >Could you please update Documentation/filesystems/f2fs.rst as well? > >Thanks,
Sure, I will make it next patch.
Thanks
>> >> Signed-off-by: Daejun Park <daejun7.park@samsung.com> >> --- >> fs/f2fs/segment.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >> index 1596502f7375..7b42bb10c6c3 100644 >> --- a/fs/f2fs/segment.c >> +++ b/fs/f2fs/segment.c >> @@ -3208,7 +3208,7 @@ enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi, >> return WRITE_LIFE_EXTREME; >> } else if (type == NODE) { >> if (temp == WARM || temp == HOT) >> - return WRITE_LIFE_NOT_SET; >> + return WRITE_LIFE_SHORT; >> else if (temp == COLD) >> return WRITE_LIFE_NONE; >> } else if (type == META) { >> > >
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