Hi Ryusuke, On 2014-02-05 03:16, Andreas Rohner wrote: > This patch adds an additional parameter min_reclaimable_blks to > the nilfs_reclaim_params structure. This parameter specifies the > minimum number of reclaimable blocks in a segment, before it can be > cleaned. If a segment is below this threshold, it is considered to > be not worth cleaning, because all the live blocks would need to be > moved to a new segment, which is expensive, and the number of > reclaimable blocks is too low. But it is still necessary to update > the segment usage information to turn the old segment into a new > one. > > This is basically a shortcut to cleaning the segment. It is still > necessary to read the segment summary information, but the writing > of the live blocks can be skipped if it's not worth it. > > This optimization can be enabled and disabled by the > use_set_suinfo switch in the configuration file. If the kernel > doesn't support the set_suinfo ioctl it returns the error > number ENOTTY, which also permanently disables the optimization. > > Signed-off-by: Andreas Rohner <[email protected]> > --- > include/nilfs_gc.h | 7 +++--- > lib/gc.c | 63 > +++++++++++++++++++++++++++++++++++++++++++++--- > sbin/cleanerd/cleanerd.c | 18 +++++++++++--- > 3 files changed, 77 insertions(+), 11 deletions(-) > > diff --git a/include/nilfs_gc.h b/include/nilfs_gc.h > index e49cbf4..1196c55 100644 > --- a/include/nilfs_gc.h > +++ b/include/nilfs_gc.h > @@ -17,18 +17,19 @@ > /* flags for nilfs_reclaim_params struct */ > #define NILFS_RECLAIM_PARAM_PROTSEQ (1UL << 0) > #define NILFS_RECLAIM_PARAM_PROTCNO (1UL << 1) > -#define __NR_NILFS_RECLAIM_PARAMS 2 > +#define NILFS_RECLAIM_PARAM_DEFERRABLE (1UL << 2) > +#define __NR_NILFS_RECLAIM_PARAMS 3 > > /** > * struct nilfs_reclaim_params - structure to specify GC parameters > * @flags: flags of valid fields > - * @reserved: padding bytes > + * @min_reclaimable_blks: minimum number of reclaimable blocks > * @protseq: start of sequence number of protected segments > * @protcno: start number of checkpoint to be protected > */ > struct nilfs_reclaim_params { > unsigned long flags; > - unsigned long reserved; > + unsigned long min_reclaimable_blks; > __u64 protseq; > nilfs_cno_t protcno; > }; > diff --git a/lib/gc.c b/lib/gc.c > index 71c7307..4aa6a2c 100644 > --- a/lib/gc.c > +++ b/lib/gc.c > @@ -29,6 +29,10 @@ > #include <syslog.h> > #endif /* HAVE_SYSLOG_H */ > > +#if HAVE_SYS_TIME_H > +#include <sys/time.h> > +#endif /* HAVE_SYS_TIME */ > + > #include <errno.h> > #include <assert.h> > #include <stdarg.h> > @@ -617,8 +621,11 @@ int nilfs_xreclaim_segment(struct nilfs *nilfs, > struct nilfs_vector *vdescv, *bdescv, *periodv, *vblocknrv; > sigset_t sigset, oldset, waitset; > nilfs_cno_t protcno; > - ssize_t n, ret = -1; > + ssize_t n, i, ret = -1; > size_t nblocks; > + __u32 reclaimable_blocks; > + struct nilfs_suinfo_update *supv; > + struct timeval tv; > > if (!(params->flags & NILFS_RECLAIM_PARAM_PROTSEQ) || > (params->flags & (~0UL << __NR_NILFS_RECLAIM_PARAMS))) { > @@ -703,13 +710,16 @@ int nilfs_xreclaim_segment(struct nilfs *nilfs, > if (ret < 0) > goto out_lock; > > + reclaimable_blocks = (nilfs_get_blocks_per_segment(nilfs) * n) - > + (nilfs_vector_get_size(vdescv) + > + nilfs_vector_get_size(bdescv)); > + > if (stat) { > stat->live_pblks = nilfs_vector_get_size(bdescv); > stat->defunct_pblks = nblocks - stat->live_pblks; > > stat->live_blks = stat->live_vblks + stat->live_pblks; > - stat->defunct_blks = n * nilfs_get_blocks_per_segment(nilfs) - > - stat->live_blks; > + stat->defunct_blks = reclaimable_blocks; > } > if (dryrun) > goto out_lock; > @@ -725,6 +735,51 @@ int nilfs_xreclaim_segment(struct nilfs *nilfs, > goto out_lock; > } > > + /* if there are less reclaimable blocks than the > + * minimal threshold try to update suinfo > + * instead of cleaning */ > + if ((params->flags & NILFS_RECLAIM_PARAM_DEFERRABLE) && > + reclaimable_blocks < params->min_reclaimable_blks * n) { > + if (stat) > + stat->deferred_segs = n; > + > + ret = gettimeofday(&tv, NULL); > + if (ret < 0) > + goto out_lock; > + > + supv = malloc(sizeof(struct nilfs_suinfo_update) * n); > + if (supv == NULL) { > + ret = -1; > + goto out_lock; > + }
I have already changed nilfs_xreclaim_segments to use nilfs_vector_create for supv instead of malloc and free directly. Don't know why I originally used malloc, since the rest of the function uses the nilfs_vector API. Regards, Andreas Rohner -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
