Is it possible to collect the very same stats (distribution of sizes and distribution of lat) without having static maps in kernel but with eBPF tracing? Like using https://github.com/iovisor/bcc/tree/master/tools/ * biolatency for lat distribution * bitesize for size distribution Please, have a look at these and similar tools (biolatpcts, biosnoop). Check the examples they have https://github.com/iovisor/bcc/blob/master/tools/bitesize_example.txt https://github.com/iovisor/bcc/blob/master/tools/biolatency_example.txt Let me know what is the difference comparing to your stats. Best Regards Aleksei Marov On Mon, 2020-07-13 at 23:13 +0200, Guoqing Jiang wrote: > With the sector table, so we can know the distribution of > different IO size from upper layer, which means we could > have the opportunity to tune the performance based on the > mostly issued IOs. > > Signed-off-by: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxxxxxxxx> > Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx> > --- > block/Kconfig | 3 ++- > block/blk-core.c | 16 ++++++++++++++++ > block/genhd.c | 21 +++++++++++++++++++++ > include/linux/part_stat.h | 3 ++- > 4 files changed, 41 insertions(+), 2 deletions(-) > > diff --git a/block/Kconfig b/block/Kconfig > index 360f63111e2d..c9b9f99152d8 100644 > --- a/block/Kconfig > +++ b/block/Kconfig > @@ -180,7 +180,8 @@ config BLK_ADDITIONAL_DISKSTAT > bool "Block layer additional diskstat" > default n > help > - Enabling this option adds io latency statistics for each block device. > + Enabling this option adds io latency and io size statistics for each > + block device. > > If unsure, say N. > > diff --git a/block/blk-core.c b/block/blk-core.c > index 036eb04782de..b67aedfbcefc 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1437,6 +1437,16 @@ static void blk_additional_latency(struct hd_struct > *part, const int sgrp, > part_stat_inc(part, latency_table[idx][sgrp]); > > } > + > +static void blk_additional_sector(struct hd_struct *part, const int sgrp, > + unsigned int sectors) > +{ > + unsigned int KB = sectors / 2, idx; > + > + idx = (KB > 0) ? ilog2(KB) : 0; > + idx = (idx > (ADD_STAT_NUM - 1)) ? (ADD_STAT_NUM - 1) : idx; > + part_stat_inc(part, size_table[idx][sgrp]); > +} > #endif > > static void blk_account_io_completion(struct request *req, unsigned int > bytes) > @@ -1447,6 +1457,9 @@ static void blk_account_io_completion(struct request > *req, unsigned int bytes) > > part_stat_lock(); > part = req->part; > +#ifdef CONFIG_BLK_ADDITIONAL_DISKSTAT > + blk_additional_sector(part, sgrp, bytes >> SECTOR_SHIFT); > +#endif > part_stat_add(part, sectors[sgrp], bytes >> 9); > part_stat_unlock(); > } > @@ -1502,6 +1515,9 @@ unsigned long disk_start_io_acct(struct gendisk *disk, > unsigned int sectors, > update_io_ticks(part, now, false); > part_stat_inc(part, ios[sgrp]); > part_stat_add(part, sectors[sgrp], sectors); > +#ifdef CONFIG_BLK_ADDITIONAL_DISKSTAT > + blk_additional_sector(part, sgrp, sectors); > +#endif > part_stat_local_inc(part, in_flight[op_is_write(op)]); > part_stat_unlock(); > > diff --git a/block/genhd.c b/block/genhd.c > index f5d2f110fb34..cb9394521a8f 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -1441,6 +1441,26 @@ static ssize_t io_latency_show(struct device *dev, > struct device_attribute *attr > > static struct device_attribute dev_attr_io_latency = > __ATTR(io_latency, 0444, io_latency_show, NULL); > + > +static ssize_t io_size_show(struct device *dev, struct device_attribute > *attr, char *buf) > +{ > + struct hd_struct *p = dev_to_part(dev); > + size_t count = 0; > + int i, sgrp; > + > + for (i = 0; i < ADD_STAT_NUM; i++) { > + count += scnprintf(buf + count, PAGE_SIZE - count, "%5d KB: ", 1 > << i); > + for (sgrp = 0; sgrp < NR_STAT_GROUPS; sgrp++) > + count += scnprintf(buf + count, PAGE_SIZE - count, "%lu > ", > + part_stat_read(p, > size_table[i][sgrp])); > + count += scnprintf(buf + count, PAGE_SIZE - count, "\n"); > + } > + > + return count; > +} > + > +static struct device_attribute dev_attr_io_size = > + __ATTR(io_size, 0444, io_size_show, NULL); > #endif > > static struct attribute *disk_attrs[] = { > @@ -1464,6 +1484,7 @@ static struct attribute *disk_attrs[] = { > #endif > #ifdef CONFIG_BLK_ADDITIONAL_DISKSTAT > &dev_attr_io_latency.attr, > + &dev_attr_io_size.attr, > #endif > NULL > }; > diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h > index fe3def8c69d7..2b056cd70d1f 100644 > --- a/include/linux/part_stat.h > +++ b/include/linux/part_stat.h > @@ -11,10 +11,11 @@ struct disk_stats { > unsigned long merges[NR_STAT_GROUPS]; > #ifdef CONFIG_BLK_ADDITIONAL_DISKSTAT > /* > - * We measure latency (ms) for 1, 2, ..., 1024 and >=1024. > + * We measure latency (ms) and size (sector) for 1, 2, ..., 1024 and >=1024. > */ > #define ADD_STAT_NUM 12 > unsigned long latency_table[ADD_STAT_NUM][NR_STAT_GROUPS]; > + unsigned long size_table[ADD_STAT_NUM][NR_STAT_GROUPS]; > #endif > unsigned long io_ticks; > local_t in_flight[2];
