Bart, > On Jul 24, 2016, at 22:37, Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > > If there are 10K zones and since queue_zoned_show() is limited to one page then only a very small fraction of the zone information will be available through sysfs. I remember from your presentations that reading the zone information is slow. Is 10K zones a typical value or a worst case value? Our 10 TB drive with 256 MB zones has 37256 zones. A drive with the same capacity and 128 MB zones will double that (there are some out there with 128 MB zones). And higher capacities are coming. So 100K+ zones is not unrealistic in the very near future. I think that what Hannes proposed, i.e. to have the zoned file only specify the zone size (so only one value), is OK as long as we also add an ioctl to get the detailed zone information, which would be much faster for applications than using something like libzbc which will be sending SG_IOs to retrieve the zone information from the disk. Best regards. ------------------------ Damien Le Moal, Ph.D. Sr. Manager, System Software Group, HGST Research, HGST, a Western Digital brand Damien.LeMoal@xxxxxxxx (+81) 0466-98-3593 (ext. 513593) 1 kirihara-cho, Fujisawa, Kanagawa, 252-0888 Japan www.hgst.com Western Digital Corporation (and its subsidiaries) E-mail Confidentiality Notice & Disclaimer: This e-mail and any files transmitted with it may contain confidential or legally privileged information of WDC and/or its affiliates, and are intended solely for the use of the individual or entity to which they are addressed. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited. If you have received this e-mail in error, please notify the sender immediately and delete the e-mail in its entirety from your system. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
