On Mon, Apr 02, 2018 at 10:07:01PM +0000, Hugo Mills wrote: > On Mon, Apr 02, 2018 at 06:03:00PM -0400, Fedja Beader wrote: > > Is there some testing utility for this? Is there a way to extract this/tell > > with a high enough certainty from datasheets/other material before purchase? > > Given that not implementing barriers is basically a bug in the > hardware [for SATA or SAS], I don't think anyone's going to specify > anything other than "fully suppors barriers" in their datasheets. > > I don't know of a testing tool. It may not be obvious that barriers > aren't being honoured without doing things like power-failure testing.
And you'd need to do a lot of power-cycling during writes, with various write patterns -- as unless you have a case of "let's lie about barriers to make benchmarks better than the competition" where barriers are consistently absent, it might be a genuine bug in a well-meaning controller that at least tries but sometimes fails to. The intentional case is usually easy to detect -- but just wait go get volkswagenized. :/ Meow! -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢰⠒⠀⣿⡁ ⢿⡄⠘⠷⠚⠋⠀ ... what's the frequency of that 5V DC? ⠈⠳⣄⠀⠀⠀⠀ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
