On 24.01.2017 15:14, Konstantin Belousov wrote: > On Tue, Jan 24, 2017 at 12:13:41PM +0000, Alexander Motin wrote: >> Author: mav >> Date: Tue Jan 24 12:13:41 2017 >> New Revision: 312694 >> URL: https://svnweb.freebsd.org/changeset/base/312694 >> >> Log: >> Make CTL ramdisk backend a real RAM disk. >> >> If "capacity" LU option is set, ramdisk backend now implements featured >> thin provisioned disk, storing data in malloc(9) allocated memory blocks >> of pblocksize bytes (default PAGE_SIZE or 4KB). Additionally ~0.2% of LU >> size is used for indirection tree (bigger pblocksize reduce the overhead). >> Backend supports all unmap and anchor operations. If configured capacity >> is overflowed, proper error conditions are reported. >> >> If "capacity" LU option is not set, the backend operates mostly the same >> as before without allocating real storage: writes go to nowhere, reads >> return zeroes, reporting that all LBAs are unmapped. >> >> This backend is still mostly oriented on testing and benchmarking (it is >> still a volatile RAM disk), but now it should allow to run real FS tests, >> not only simple dumb dd. > > This sounds too much like malloc-backed md(4).
Yes, it is. Just without memory copies and GEOM calls, and with some additional SCSI features. -- Alexander Motin _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
