On Mon, 7 Nov 2011 17:09:57 +0200 Alexander Nezhinsky <alexandern@xxxxxxxxxxxx> wrote: > To enable submitting batches of scsi commands by the backing stores, > NOT_LAST bit is added to the command state. > This integrates the batching feature seamlessly both for the LLDs and the > backing stores: > - the backing stores not supporting batched mode can safely disregard NOT_LAST > bit and submit all commands separately (as previously); > - the LLDs can also ignore the bit and not set it at all, as the default > value NOT_LAST=0 means that each command is "last" (i.e. separately submitted, > in this context), so that even the backing stores which do support batching > will make no attempt to batch it. > - when both LLD and BS support batching, the LLDs which accumulate scsi cmds > may submit them marking all but the last one with NOT_LAST=1. The BS is > hinted to queue the commands marked with NOT_LAST=1 until a command marked > NOT_LAST=0 is submitted, then all the commands previously queued can > be submitted, if approppriate. The NOT_LAST=0 bit only instructs the BS that > the currently available batch is complete, so that more commands may > not arrive for quite a long time, but the BS may decide to actually > separate or combine these "batches" according to its own algorithms. > > Signed-off-by: Alexander Nezhinsky <alexandern@xxxxxxxxxxxx> > --- > usr/scsi_cmnd.h | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) All applied, thanks! -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
