Hi Jaegeuk, > -----Original Message----- > From: linux-fsdevel-owner@xxxxxxxxxxxxxxx [mailto:linux-fsdevel-owner@xxxxxxxxxxxxxxx] On > Behalf Of Jaegeuk Kim > Sent: Wednesday, January 28, 2015 7:32 AM > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: Jaegeuk Kim > Subject: [PATCH 5/5] f2fs: introduce a batched trim > > This patch introduces a batched trimming feature, which submits split discard > commands. I didn't get it, why we should split discard commands. :( Does smaller discarding for flash shows better performance or effect or safety? Can you please explain more about this patch? Thanks, > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > --- > fs/f2fs/f2fs.h | 1 + > fs/f2fs/segment.c | 15 ++++++++++----- > 2 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index c0b83d6..ec4d16b 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -104,6 +104,7 @@ enum { > CP_DISCARD, > }; > > +#define BATCHED_TRIM_SEGMENTS 10 > struct cp_control { > int reason; > __u64 trim_start; > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 31c4e57..6c9c784 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -1066,14 +1066,19 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range) > end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 : > GET_SEGNO(sbi, end); > cpc.reason = CP_DISCARD; > - cpc.trim_start = start_segno; > - cpc.trim_end = end_segno; > cpc.trim_minlen = range->minlen >> sbi->log_blocksize; > > /* do checkpoint to issue discard commands safely */ > - mutex_lock(&sbi->gc_mutex); > - write_checkpoint(sbi, &cpc); > - mutex_unlock(&sbi->gc_mutex); > + for (; start_segno <= end_segno; > + start_segno += BATCHED_TRIM_SEGMENTS + 1) { > + cpc.trim_start = start_segno; > + cpc.trim_end = min_t(unsigned int, > + start_segno + BATCHED_TRIM_SEGMENTS, end_segno); > + > + mutex_lock(&sbi->gc_mutex); > + write_checkpoint(sbi, &cpc); > + mutex_unlock(&sbi->gc_mutex); > + } > out: > range->len = cpc.trimmed << sbi->log_blocksize; > return 0; > -- > 2.1.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
