d25a176029
used to align partitions in gpart. We also try to align partitions by stripe size when creating new media. Align these two concepts by making fwsectors the same as the stripe size. Select a sensible number of heads so we wind up with about 20 cylinders. This number was selected to keep the rounding effects to a few percent while keeping the number of cylinder groups low. Sadly, it is not possible to make these numbers match the numbers used by SD card readers. There apperas to be much variation between brands so there's no one universal number. These numbers are also not aligned to the stripe size, so some performance problems may still be present when SD cards are created this way. Also, these numbers will differ from the far less common SD to ATA adapters, which present a different, but more uniform, set of numbers that also happened to match the old defaults. Nothing should change for current users. Any suboptimal performance caused by misalignment will still be there. gpart will honor the partitions that aren't on proper boudnaries, but editing the partition tables may result in different alignments being used than before when editing things natively. Ideally, there'd be some way to override these values in the disk subsystem by the user for the USB adapter use case where all "native" notions of geometry disappear. This does not implement that. |
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| .. | ||
| host | ||
| bridge.h | ||
| mmc.c | ||
| mmcbr_if.m | ||
| mmcbrvar.h | ||
| mmcbus_if.m | ||
| mmcreg.h | ||
| mmcsd.c | ||
| mmcvar.h | ||