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  1. 04 Aug, 2006 1 commit
    • Ilpo Järvinen's avatar
      [PKT_SCHED] RED: Fix overflow in calculation of queue average · c4c0ce5c
      Ilpo Järvinen authored 
      

Overflow can occur very easily with 32 bits, e.g., with 1 second
us_idle is approx. 2^20, which leaves only 11-Wlog bits for queue
length. Since the EWMA exponent is typically around 9, queue
lengths larger than 2^2 cause overflow. Whether the affected
branch is taken when us_idle is as high as 1 second, depends on
Scell_log, but with rather reasonable configuration Scell_log is
large enough to cause p->Stab to have zero index, which always
results zero shift (typically also few other small indices result
in zero shift).
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c4c0ce5c
  3. 03 Aug, 2006 11 commits
  5. 02 Aug, 2006 15 commits
  7. 31 Jul, 2006 11 commits
  9. 29 Jul, 2006 2 commits
    • Andi Kleen's avatar
      [PATCH] x86_64: Fix swiotlb=force · 65f87d8a
      Andi Kleen authored 
      

It was broken before. But having it is important as possible hardware
bug workaround.

And previously there was no way to force swiotlb if there is another IOMMU.
Side effect is that iommu=force won't force swiotlb anymore even if there
isn't another IOMMU.
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      65f87d8a
    • Jon Mason's avatar
      [PATCH] x86_64: Calgary IOMMU - Multi-Node NULL pointer dereference fix · d2105b10
      Jon Mason authored 
      

Calgary hits a NULL pointer dereference when booting in a multi-chassis
NUMA system.  See Redhat bugzilla number 198498, found by Konrad
Rzeszutek (konradr@redhat.com).

There are many issues that had to be resolved to fix this problem.
Firstly when I originally wrote the code to handle NUMA systems, I
had a large misunderstanding that was not corrected until now.  That was
that I thought the "number of nodes online" referred to number of
physical systems connected.  So that if NUMA was disabled, there
would only be 1 node and it would only show that node's PCI bus.
In reality if NUMA is disabled, the system displays all of the
connected chassis as one node but is only ignorant of the delays
in accessing main memory.  Therefore, references to num_online_nodes()
and MAX_NUMNODES are incorrect and need to be set to the maximum
number of nodes that can be accessed (which are 8).  I created a
variable, MAX_NUM_CHASSIS, and set it to 8 to fix this.

Secondly, when walking the PCI in detect_calgary, the code only
checked the first "slot" when looking to see if a device is present.
This will work for most cases, but unfortunately it isn't always the
case.  In the NUMA MXE drawers, there are USB devices present on the
3rd slot (with slot 1 being empty).  So, to work around this, all
slots (up to 8) are scanned to see if there are any devices present.

Lastly, the bus is being enumerated on large systems in a different
way the we originally thought.  This throws the ugly logic we had
out the window.  To more elegantly handle this, I reorganized the
kva array to be sparse (which removed the need to have any bus number
to kva slot logic in tce.c) and created a secondary space array to
contain the bus number to phb mapping.

With these changes Calgary boots on an x460 with 4 nodes with and
without NUMA enabled.
Signed-off-by: default avatarJon Mason <jdmason@us.ibm.com>
Signed-off-by: default avatarMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d2105b10