Messages in this thread | | | Subject | Re: [f2fs-dev] [PATCH] f2fs: change write_hint for hot/warm nodes | From | Chao Yu <> | Date | Tue, 3 Nov 2020 16:28:49 +0800 |
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On 2020/11/3 14:40, Daejun Park wrote: >>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,
> > 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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