On Jan 21, 2014, at 4:59 PM, Andreas Rohner wrote: > With this option the user can specify the minimal number of free/dead > blocks before a segment can be cleaned.
"Free or dead" or "free and dead"? What do you mean by free blocks? "Free blocks" sounds for me as blocks that I can allocate and to use immediately without any operations. If you mean invalid blocks (blocks that it was updated in this segment) then I need to do garbage collection operation for making it free. So, free blocks are really confusing term. And "dead blocks" sounds for me not very good. > This is a threshold for the GC > to prevent needless moving of data. If there are less free blocks > to gain from cleaning a segment than the specified number, the GC will > abort and try again with a different segment. > > By setting it to 0 this feature is effectively disabled. > > Signed-off-by: Andreas Rohner <[email protected]> > --- > include/nilfs_cleaner.h | 19 ++++++++++--------- > sbin/cleanerd/cldconfig.c | 40 +++++++++++++++++++++++++++++++++++++++ > sbin/cleanerd/cldconfig.h | 4 ++++ > sbin/cleanerd/cleanerd.c | 23 ++++++++++++++++++++++ > sbin/cleanerd/nilfs_cleanerd.conf | 9 +++++++++ > sbin/nilfs-clean/nilfs-clean.c | 18 ++++++++++++++---- > 6 files changed, 100 insertions(+), 13 deletions(-) > > diff --git a/include/nilfs_cleaner.h b/include/nilfs_cleaner.h > index 0bf02aa..42c4aa7 100644 > --- a/include/nilfs_cleaner.h > +++ b/include/nilfs_cleaner.h > @@ -46,17 +46,18 @@ struct nilfs_cleaner_args { > uint64_t start_segnum; /* start segment number */ > uint64_t nsegs; /* number of segments */ > uint32_t runtime; /* runtime in seconds */ > - uint32_t pad2; > + uint32_t min_free_blocks_threshold; > }; > /* valid flags */ > -#define NILFS_CLEANER_ARG_PROTECTION_PERIOD (1 << 0) > -#define NILFS_CLEANER_ARG_NSEGMENTS_PER_CLEAN (1 << 1) > -#define NILFS_CLEANER_ARG_CLEANING_INTERVAL (1 << 2) > -#define NILFS_CLEANER_ARG_USAGE_RATE_THRESHOLD (1 << 3) /* reserved */ > -#define NILFS_CLEANER_ARG_START_SEGNUM (1 << 4) /* reserved */ > -#define NILFS_CLEANER_ARG_NSEGS (1 << 5) /* reserved */ > -#define NILFS_CLEANER_ARG_NPASSES (1 << 6) /* reserved */ > -#define NILFS_CLEANER_ARG_RUNTIME (1 << 7) /* reserved */ > +#define NILFS_CLEANER_ARG_PROTECTION_PERIOD (1 << 0) > +#define NILFS_CLEANER_ARG_NSEGMENTS_PER_CLEAN (1 << 1) > +#define NILFS_CLEANER_ARG_CLEANING_INTERVAL (1 << 2) > +#define NILFS_CLEANER_ARG_USAGE_RATE_THRESHOLD (1 << 3) /* > reserved */ > +#define NILFS_CLEANER_ARG_START_SEGNUM (1 << 4) /* > reserved */ > +#define NILFS_CLEANER_ARG_NSEGS (1 << 5) /* > reserved */ > +#define NILFS_CLEANER_ARG_NPASSES (1 << 6) /* reserved */ > +#define NILFS_CLEANER_ARG_RUNTIME (1 << 7) /* reserved */ > +#define NILFS_CLEANER_ARG_MIN_FREE_BLOCKS_THRESHOLD (1 << 8) What about NILFS_CLEANER_ARG_MIN_FBLK_THRESHOLD? But free blocks really confuse me. > > enum { > NILFS_CLEANER_STATUS_IDLE, > diff --git a/sbin/cleanerd/cldconfig.c b/sbin/cleanerd/cldconfig.c > index 270d360..4d7589c 100644 > --- a/sbin/cleanerd/cldconfig.c > +++ b/sbin/cleanerd/cldconfig.c > @@ -456,6 +456,34 @@ nilfs_cldconfig_handle_mc_nsegments_per_clean(struct > nilfs_cldconfig *config, > } > > static int > +nilfs_cldconfig_handle_min_free_blocks(struct nilfs_cldconfig *config, > + char **tokens, size_t ntoks, > + struct nilfs *nilfs) > +{ > + unsigned long n; > + > + if (nilfs_cldconfig_get_ulong_argument(tokens, ntoks, &n) < 0) > + return 0; > + > + config->cf_min_free_blocks_threshold = n; > + return 0; > +} > + > +static int > +nilfs_cldconfig_handle_mc_min_free_blocks(struct nilfs_cldconfig *config, > + char **tokens, size_t ntoks, > + struct nilfs *nilfs) > +{ > + unsigned long n; > + > + if (nilfs_cldconfig_get_ulong_argument(tokens, ntoks, &n) < 0) > + return 0; > + > + config->cf_mc_min_free_blocks_threshold = n; > + return 0; > +} > + > +static int > nilfs_cldconfig_handle_cleaning_interval(struct nilfs_cldconfig *config, > char **tokens, size_t ntoks, > struct nilfs *nilfs) > @@ -576,6 +604,14 @@ nilfs_cldconfig_keyword_table[] = { > "log_priority", 2, 2, > nilfs_cldconfig_handle_log_priority > }, > + { > + "min_free_blocks_threshold", 2, 2, > + nilfs_cldconfig_handle_min_free_blocks > + }, > + { > + "mc_min_free_blocks_threshold", 2, 2, > + nilfs_cldconfig_handle_mc_min_free_blocks > + }, > }; > > #define NILFS_CLDCONFIG_NKEYWORDS \ > @@ -641,6 +677,10 @@ static void nilfs_cldconfig_set_default(struct > nilfs_cldconfig *config, > config->cf_retry_interval.tv_usec = 0; > config->cf_use_mmap = NILFS_CLDCONFIG_USE_MMAP; > config->cf_log_priority = NILFS_CLDCONFIG_LOG_PRIORITY; > + config->cf_min_free_blocks_threshold = > + NILFS_CLDCONFIG_MIN_FREE_BLOCKS_THRESHOLD; > + config->cf_mc_min_free_blocks_threshold = > + NILFS_CLDCONFIG_MC_MIN_FREE_BLOCKS_THRESHOLD; > } > > static inline int iseol(int c) > diff --git a/sbin/cleanerd/cldconfig.h b/sbin/cleanerd/cldconfig.h > index 188ce9b..49ee6be 100644 > --- a/sbin/cleanerd/cldconfig.h > +++ b/sbin/cleanerd/cldconfig.h > @@ -102,6 +102,8 @@ struct nilfs_cldconfig { > struct timeval cf_retry_interval; > int cf_use_mmap; > int cf_log_priority; > + unsigned long cf_min_free_blocks_threshold; > + unsigned long cf_mc_min_free_blocks_threshold; > }; > > #define NILFS_CLDCONFIG_SELECTION_POLICY_IMPORTANCE \ > @@ -120,6 +122,8 @@ struct nilfs_cldconfig { > #define NILFS_CLDCONFIG_RETRY_INTERVAL 60 > #define NILFS_CLDCONFIG_USE_MMAP 1 > #define NILFS_CLDCONFIG_LOG_PRIORITY LOG_INFO > +#define NILFS_CLDCONFIG_MIN_FREE_BLOCKS_THRESHOLD 256 > +#define NILFS_CLDCONFIG_MC_MIN_FREE_BLOCKS_THRESHOLD 128 Why 256 or 128? What is good? What is bad? I am a user. How can I define what value is appropriate? How should I think for choosing some value? For example, I want to have the fastest performance as possible. How can I define an appropriate value? Or, maybe, I want to clean as many segments as possible. How should I think? Or, maybe, I want combination of GC policies. Thanks, Vyacheslav Dubeyko. -- 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
