That sounds like a bug in bcache - bcache should be respecting the queue limits the underlying device exports. Can you tell me what the various files in /sys/block/<device>/queue/ look like for your device? On Wed, May 9, 2012 at 8:23 PM, moussa ba <musaba@xxxxxxxxx> wrote: > Tried to send this to mailing list but was rejected somehow. > > ---------- Forwarded message ---------- > From: moussa ba <musaba@xxxxxxxxx> > Date: Wed, May 9, 2012 at 5:17 PM > Subject: Scatter Gather List in bio exceed driver capabilities > To: linux-bcache@xxxxxxxxxxxxxxx > > > > We are using a micron PCI-E SSD as a caching device. I am running into > issues where the driver would fail when we try to register the cache device. > The failure is because bcache sends down a bio with 256 entries while the > device driver can only handle 128 entries. We could make changes inside our > driver to chunk the requests (mind you I did not write the driver, but > driver guys told me so...) and fix it that way. I am assuming that since > bcache is creating the bio to get at its metadata, it does not chunk the > bios to fit the underlying hardware nor does it query it in some way to set > the bi_vcnt. > > Any suggestions on how to properly address this? > > Moussa > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
