Messages in this thread |  | | Date | Tue, 25 Feb 2014 02:58:24 +0300 | From | Sergey Senozhatsky <> | Subject | Re: [PATCHv6 5/6] zram: enalbe multi stream compression support in zram |
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On (02/25/14 08:53), Minchan Kim wrote: > On Fri, Feb 21, 2014 at 02:50:42PM +0300, Sergey Senozhatsky wrote: > > 1) Add ZRAM_MULTI_STREAM configuration option and make multi stream > > zcomp support available. > > > > 2) Introduce zram device attribute max_comp_streams to show and store > > current zcomp's max number of zcomp streams (num_strm). > > > > 3) Extend zcomp zcomp_create() with `num_strm' parameter. `num_strm' > > limits the number of zcomp_strm structs in compression backend's idle > > list (max_comp_streams). > > > > If ZRAM_MULTI_STREAM option selected: > > -- user can change max number of compression streams (max_comp_streams), > > otherwise, attempt to change its default value (1) will be ignored. > > -- passing to zcomp_create() num_strm equals to 1 will initialise zcomp > > using single compression stream zcomp_strm_single (mutex-based locking) > > -- passing to zcomp_create() num_strm greater than 1 will initialise zcomp > > using multi compression stream zcomp_strm_multi (spinlock-based locking) > > > > If ZRAM_MULTI_STREAM has not been selected, only single compression stream > > support available. > > > > iozone -t 3 -R -r 16K -s 60M -I +Z > > > > test base 1 strm (mutex) 3 strm (spinlock) > > ----------------------------------------------------------------------- > > Initial write 589286.78 583518.39 718011.05 > > Rewrite 604837.97 596776.38 1515125.72 > > Random write 584120.11 595714.58 1388850.25 > > Pwrite 535731.17 541117.38 739295.27 > > Fwrite 1418083.88 1478612.72 1484927.06 > > > > Usage example: > > set max_comp_streams to 4 > > echo 4 > /sys/block/zram0/max_comp_streams > > > > show current max_comp_streams (default value is 1). > > cat /sys/block/zram0/max_comp_streams > > > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > > --- > > drivers/block/zram/Kconfig | 10 ++++++++++ > > drivers/block/zram/zcomp.c | 13 +++++++++++-- > > drivers/block/zram/zcomp.h | 2 +- > > drivers/block/zram/zram_drv.c | 43 ++++++++++++++++++++++++++++++++++++++++++- > > drivers/block/zram/zram_drv.h | 2 +- > > 5 files changed, 65 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > index 3450be8..a2ba9a9 100644 > > --- a/drivers/block/zram/Kconfig > > +++ b/drivers/block/zram/Kconfig > > @@ -15,6 +15,16 @@ config ZRAM > > > > See zram.txt for more information. > > > > +config ZRAM_MULTI_STREAM > > + bool "Multi stream compression support" > > + depends on ZRAM > > + default n > > + help > > + This option adds additional functionality to ZRAM, that enables > > + multi compression stream support and provides ability to control > > + maximum number of parallel compressions using max_comp_streams > > + device attribute. > > + > > config ZRAM_DEBUG > > bool "Compressed RAM block device debug support" > > depends on ZRAM > > diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c > > index 41325ed..7faa6bd 100644 > > --- a/drivers/block/zram/zcomp.c > > +++ b/drivers/block/zram/zcomp.c > > @@ -240,8 +240,9 @@ void zcomp_destroy(struct zcomp *comp) > > * if requested algorithm is not supported or in case > > * of init error > > */ > > -struct zcomp *zcomp_create(const char *compress) > > +struct zcomp *zcomp_create(const char *compress, int num_strm) > > { > > + int ret; > > struct zcomp *comp; > > struct zcomp_backend *backend; > > > > @@ -254,7 +255,15 @@ struct zcomp *zcomp_create(const char *compress) > > return NULL; > > > > comp->backend = backend; > > - if (zcomp_strm_single_create(comp) != 0) { > > +#ifdef CONFIG_ZRAM_MULTI_STREAM > > + if (num_strm > 1) > > + ret = zcomp_strm_multi_create(comp, num_strm); > > + else > > + ret = zcomp_strm_single_create(comp); > > +#else > > + ret = zcomp_strm_single_create(comp); > > +#endif > > + if (ret != 0) { > > zcomp_destroy(comp); > > return NULL; > > } > > diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h > > index 8dc1d7f..d7e1229 100644 > > --- a/drivers/block/zram/zcomp.h > > +++ b/drivers/block/zram/zcomp.h > > @@ -42,7 +42,7 @@ struct zcomp { > > void (*destroy)(struct zcomp *comp); > > }; > > > > -struct zcomp *zcomp_create(const char *comp); > > +struct zcomp *zcomp_create(const char *comp, int num_strm); > > void zcomp_destroy(struct zcomp *comp); > > > > struct zcomp_strm *zcomp_strm_get(struct zcomp *comp); > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > > index 200c12a..c147e6f 100644 > > --- a/drivers/block/zram/zram_drv.c > > +++ b/drivers/block/zram/zram_drv.c > > @@ -107,6 +107,42 @@ static ssize_t mem_used_total_show(struct device *dev, > > return sprintf(buf, "%llu\n", val); > > } > > > > +static ssize_t max_comp_streams_show(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + long val; > > Why 'long'? > > > + struct zram *zram = dev_to_zram(dev); > > + > > + down_read(&zram->init_lock); > > + val = zram->max_comp_streams; > > + up_read(&zram->init_lock); > > + > > + return sprintf(buf, "%ld\n", val); > > +} > > + > > +static ssize_t max_comp_streams_store(struct device *dev, > > + struct device_attribute *attr, const char *buf, size_t len) > > +{ > > +#ifdef CONFIG_ZRAM_MULTI_STREAM > > + long num; > > + struct zram *zram = dev_to_zram(dev); > > + > > + if (kstrtol(buf, 0, &num)) > > + return -EINVAL; > > + if (num < 1) > > + return -EINVAL; > > + down_write(&zram->init_lock); > > + if (init_done(zram)) { > > + up_write(&zram->init_lock); > > + pr_info("Can't set max_comp_streams for initialized device\n"); > > + return -EBUSY; > > + } > > + zram->max_comp_streams = num; > > + up_write(&zram->init_lock); > > If user decrease max stream in runtime, who care of freeing streams? >
at the moment (to make it simpler), user can set max stream number only for un-initialised device. once zcomp created and initialised user cannot change max streams
pr_info("Can't set max_comp_streams for initialized device\n");
> > +#endif > > + return len; > > +} > > + > > /* flag operations needs meta->tb_lock */ > > static int zram_test_flag(struct zram_meta *meta, u32 index, > > enum zram_pageflags flag) > > @@ -503,6 +539,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) > > > > zcomp_destroy(zram->comp); > > zram->comp = NULL; > > + zram->max_comp_streams = 1; > > > > zram_meta_free(zram->meta); > > zram->meta = NULL; > > @@ -532,7 +569,7 @@ static ssize_t disksize_store(struct device *dev, > > return -EBUSY; > > } > > > > - zram->comp = zcomp_create(default_compressor); > > + zram->comp = zcomp_create(default_compressor, zram->max_comp_streams); > > if (!zram->comp) { > > up_write(&zram->init_lock); > > pr_info("Cannot initialise compressing backend\n"); > > @@ -695,6 +732,8 @@ static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); > > static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); > > static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); > > static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); > > +static DEVICE_ATTR(max_comp_streams, S_IRUGO | S_IWUSR, > > + max_comp_streams_show, max_comp_streams_store); > > > > ZRAM_ATTR_RO(num_reads); > > ZRAM_ATTR_RO(num_writes); > > @@ -719,6 +758,7 @@ static struct attribute *zram_disk_attrs[] = { > > &dev_attr_orig_data_size.attr, > > &dev_attr_compr_data_size.attr, > > &dev_attr_mem_used_total.attr, > > + &dev_attr_max_comp_streams.attr, > > NULL, > > }; > > > > @@ -782,6 +822,7 @@ static int create_device(struct zram *zram, int device_id) > > > > zram->meta = NULL; > > zram->comp = NULL; > > + zram->max_comp_streams = 1; > > return 0; > > > > out_free_disk: > > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h > > index 45e04f7..8dccb22 100644 > > --- a/drivers/block/zram/zram_drv.h > > +++ b/drivers/block/zram/zram_drv.h > > @@ -99,7 +99,7 @@ struct zram { > > * we can store in a disk. > > */ > > u64 disksize; /* bytes */ > > - > > + long max_comp_streams; > > struct zram_stats stats; > > }; > > #endif > > -- > > 1.9.0.291.g027825b > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > -- > Kind regards, > Minchan Kim >
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