Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote:
> But to be more clear, NOSSD shouldn't be a special case.
> In fact currently NOSSD only affects whether we will output the message
> "enabling ssd optimization", no real effect if I didn't miss anything.
That's not quite true. In:
if (!btrfs_test_opt(fs_info, NOSSD) &&
!fs_info->fs_devices->rotating) {
btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
}
the call to btrfs_set_and_info() will turn on SSD.
What this seems to me is that, normally, SSD will be turned on automatically
unless at least one of the devices is a rotating medium - but this appears to
be explicitly suppressed by the NOSSD option.
David