On Sun, 05 Dec 2010 11:53:03 +0100 Lukas Kolbe <lkolbe@xxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Well, 2MB blocksizes actually do work - bacula is reporting a blocksize > of ~2MB for each drive while writing to it - only after there was memory > pressure and a new tape got inserted, it is *not* possible anymore to > write to the tape with these blocksizes, and dmesg tells me one of these > every time bacula tries to read from or write to a tape: I don't know how bacula works but I guess that it closes and reopen a st device when you insert a new tape. The driver frees the memory when it closes the device. > [101883.958351] st0: Can't allocate 2097152 byte tape buffer. > [103901.666608] st0: Can't allocate 10249541 byte tape buffer. > > No idea why it's trying 10MB, though. > > I tested with the patch from Fujita, and this messages from before > applying the patch: > > [158544.348411] st: append_to_buffer offset overflow. > > do not appear anymore. > It didn't help on the not-being-able-to-write-after-memory-pressure > matter, though. There is no way to guarantee that we can allocate physically continuous large memory. > > This isn't something we can work around > > in the driver because the transaction can't be split ... it has to go > > down as a single WRITE command with a single output data buffer. > > > > The LSI 1068 is an upgradeable firmware system, so it's always possible > > LSI can come up with a firmware update that increases the size (this > > would also require a corresponding driver change), but it doesn't sound > > to be something that can be done in the driver alone. > > If only LSI's website were a little more clear on where to find updated > firmware and what was the latest version :/. n I think that Desai said that your hardware can handle more sg entries. You have a better chance to live with memory pressure. Try the following patch with my patch. You need to set FUSION_MAX_SGE to 256 with kernel meunconfig (or whatever you like) and rebuild your kernel. Make sure that the driver supports 256 entries like this: fujita@calla:~$ cat /sys/class/scsi_host/host4/sg_tablesize 256 diff --git a/drivers/message/fusion/Kconfig b/drivers/message/fusion/Kconfig index a34a11d..e70d65e 100644 --- a/drivers/message/fusion/Kconfig +++ b/drivers/message/fusion/Kconfig @@ -61,9 +61,9 @@ config FUSION_SAS LSISAS1078 config FUSION_MAX_SGE - int "Maximum number of scatter gather entries (16 - 128)" + int "Maximum number of scatter gather entries (16 - 256)" default "128" - range 16 128 + range 16 256 help This option allows you to specify the maximum number of scatter- gather entries per I/O. The driver default is 128, which matches -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
