On 08/22/2016 06:34 AM, Shaun Tancheff wrote: > Currently the RB-Tree zone cache is fast and flexible. It does > use a rather largish amount of ram. This model reduces the ram > required from 120 bytes per zone to 16 bytes per zone with a > moderate transformation of the blk_zone_lookup() api. > > This model is predicated on the belief that most variations > on zoned media will follow a pattern of using collections of same > sized zones on a single device. Similar to the pattern of erase > blocks on flash devices being progressivly larger 16K, 64K, ... > > The goal is to be able to build a descriptor which is both memory > efficient, performant, and flexible. > > Signed-off-by: Shaun Tancheff <shaun.tanch...@seagate.com> > --- > block/blk-core.c | 2 +- > block/blk-sysfs.c | 31 +- > block/blk-zoned.c | 103 +++-- > drivers/scsi/sd.c | 5 +- > drivers/scsi/sd.h | 4 +- > drivers/scsi/sd_zbc.c | 1025 > +++++++++++++++++++++++++++--------------------- > include/linux/blkdev.h | 82 +++- > 7 files changed, 716 insertions(+), 536 deletions(-) > Have you measure the performance impact here? The main idea behind using an RB-tree is that each single element will fit in the CPU cache; using an array will prevent that. So we will increase the number of cache flushes, and most likely a performance penalty, too. Hence I'd rather like to see a performance measurement here before going down that road.
Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking h...@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)
