Commit Graph

77355 Commits

Author SHA1 Message Date
Mark Fasheh
1252c434e3 ocfs2: Documentation update
Remove 'readpages' from the list in ocfs2.txt. Instead of having two
identical lists, I just removed the list in the OCFS2 section of fs/Kconfig
and added a pointer to Documentation/filesystems/ocfs2.txt.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:48:42 -08:00
Mark Fasheh
628a24f5bd ocfs2: Readpages support
Add ->readpages support to Ocfs2. This is rather trivial - all it required
is a small update to ocfs2_get_block (for mapping full extents via b_size)
and an ocfs2_readpages() function which partially mirrors ocfs2_readpage().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:48:12 -08:00
Joel Becker
d69a3ad6a0 dlm: Split lock mode and flag constants into a sharable header.
This allows others to use the DLM constants without being tied to the
function API of fs/dlm.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:46:04 -08:00
Mark Fasheh
e63aecb651 ocfs2: Rename ocfs2_meta_[un]lock
Call this the "inode_lock" now, since it covers both data and meta data.
This patch makes no functional changes.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:46:01 -08:00
Mark Fasheh
c934a92d05 ocfs2: Remove data locks
The meta lock now covers both meta data and data, so this just removes the
now-redundant data lock.

Combining locks saves us a round of lock mastery per inode and one less lock
to ping between nodes during read/write.

We don't lose much - since meta locks were always held before a data lock
(and at the same level) ordered writeout mode (the default) ensured that
flushing for the meta data lock also pushed out data anyways.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:45:57 -08:00
Mark Fasheh
f1f540688e ocfs2: Add data downconvert worker to inode lock
In order to extend inode lock coverage to inode data, we use the same data
downconvert worker with only a small modification to only do work for
regular files.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:45:54 -08:00
Mark Fasheh
34d024f843 ocfs2: Remove mount/unmount votes
The node maps that are set/unset by these votes are no longer relevant, thus
we can remove the mount and umount votes. Since those are the last two
remaining votes, we can also remove the entire vote infrastructure.

The vote thread has been renamed to the downconvert thread, and the small
amount of functionality related to managing it has been moved into
fs/ocfs2/dlmglue.c. All references to votes have been removed or updated.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:45:34 -08:00
Linus Torvalds
99f1c97dbd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (81 commits)
  RDMA/cxgb3: Fix the T3A workaround checks
  IB/ipath: Remove unnecessary cast
  IPoIB: Constify seq_operations function pointer tables
  RDMA/cxgb3: Mark QP as privileged based on user capabilities
  RDMA/cxgb3: Fix page shift calculation in build_phys_page_list()
  RDMA/cxgb3: Flush the receive queue when closing
  IB/ipath: Trivial simplification of ipath_make_ud_req()
  IB/mthca: Update latest "native Arbel" firmware revision
  IPoIB: Remove redundant check of netif_queue_stopped() in xmit handler
  IB/ipath: Add mappings from HW register to PortInfo port physical state
  IB/ipath: Changes to support PIO bandwidth check on IBA7220
  IB/ipath: Minor cleanup of unused fields and chip-specific errors
  IB/ipath: New sysfs entries to control 7220 features
  IB/ipath: Add new chip-specific functions to older chips, consistent init
  IB/ipath: Remove unused MDIO interface code
  IB/ehca: Prevent RDMA-related connection failures on some eHCA2 hardware
  IB/ehca: Add "port connection autodetect mode"
  IB/ehca: Define array to store SMI/GSI QPs
  IB/ehca: Remove CQ-QP-link before destroying QP in error path of create_qp()
  IB/iser: Add change_queue_depth method
  ...
2008-01-25 14:41:24 -08:00
Mark Fasheh
6f7b056ea9 ocfs2: Remove fs dependency on ocfs2_heartbeat module
Now that the dlm exposes domain information to us, we don't need generic
node up / node down callbacks. And since the DLM is only telling us when a
node goes down unexpectedly, we no longer need to optimize away node down
callbacks via the umount map.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:36:40 -08:00
Mark Fasheh
6561168cb4 ocfs2_dlm: Call node eviction callbacks from heartbeat handler
With this, a dlm client can take advantage of the group protocol in the dlm
to get full notification whenever a node within the dlm domain leaves
unexpectedly.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 14:36:40 -08:00
Steve Wise
8176d297c7 RDMA/cxgb3: Fix the T3A workaround checks
Correctly work around T3A issues by checking "hwtype != T3A" instead of
"hwtype == T3B".  This will be needed for new hardware types.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:47 -08:00
Jan Engelhardt
f7fca1e8a8 IB/ipath: Remove unnecessary cast
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:46 -08:00
Jan Engelhardt
1cf18d5aab IPoIB: Constify seq_operations function pointer tables
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:46 -08:00
Steve Wise
c6b5b50474 RDMA/cxgb3: Mark QP as privileged based on user capabilities
This is needed to support zero-stag properly.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:45 -08:00
Steve Wise
d08ca26cee RDMA/cxgb3: Fix page shift calculation in build_phys_page_list()
The existing logic incorrectly maps this buffer list:

    0: addr 0x10001000, size 0x1000
    1: addr 0x10002000, size 0x1000

To this bogus page list:

    0: 0x10000000
    1: 0x10002000

The shift calculation must also take into account the address of the
first entry masked by the page_mask as well as the last address+size
rounded up to the next page size.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:45 -08:00
Steve Wise
856b592504 RDMA/cxgb3: Flush the receive queue when closing
- for kernel mode cqs, call event notification handler when flushing.
- flush QP when moving from RTS -> CLOSING.
- fix logic to identify a kernel mode qp.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:45 -08:00
Ralph Campbell
4e1e93a418 IB/ipath: Trivial simplification of ipath_make_ud_req()
Move the increment of s_hdrwords into the existing if block that tests 
if we're doing a send with immediate, to save one test of the opcode.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:44 -08:00
Roland Dreier
950529e5c6 IB/mthca: Update latest "native Arbel" firmware revision
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:44 -08:00
Krishna Kumar
48fe5e594c IPoIB: Remove redundant check of netif_queue_stopped() in xmit handler
qdisc_run() now tests for queue_stopped() before calling
__qdisc_run(), and the same check is done in every iteration of
__qdisc_run(), so another check is not required in the driver xmit.
This means that ipoib_start_xmit() no longer needs to test
netif_queue_stopped(); the test was added to fix earlier kernels,
where the networking stack did not guarantee that the xmit method of
an LLTX driver would not be called after the queue was stopped, but
current kernels do provide this guarantee.

To validate, I put a debug in the TX_BUSY path which never hit with 64
threads running overnight exercising this code a few 100 million
times.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:44 -08:00
Ralph Campbell
3d68ea3261 IB/ipath: Add mappings from HW register to PortInfo port physical state
Add new mappings from port physical state (a HW register value) to the
IB SubnGet(PortInfo) port physical state.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:44 -08:00
Dave Olson
6ac50727bd IB/ipath: Changes to support PIO bandwidth check on IBA7220
The IBA7220 uses a count-based triggering mechanism, and therefore
can't use the same bandwidth verification mechanism as older chips.

To support the 7220, allow enabling and disabling armlaunch errors on
application request.  Minor robustness improvements as well.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:43 -08:00
Dave Olson
ddb70c83a5 IB/ipath: Minor cleanup of unused fields and chip-specific errors
Clean up some unused header fields, minor related cleanup.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:43 -08:00
Michael Albaugh
359193ef43 IB/ipath: New sysfs entries to control 7220 features
IBA7220 includes many more configurable IB settings. Getting/setting
these is now grouped into a pair of chip specific functions accessed via
function pointers.  Provide sysfs access to these settings.

Signed-off-by: Michael Albaugh <michael.albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:17:32 -08:00
Dave Olson
c4bce8032e IB/ipath: Add new chip-specific functions to older chips, consistent init
This adds the new (sometimes empty) chip-specific functions to the older
chips, and makes the initialization and related functions consistent across
all 3 chips.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:45 -08:00
Dave Olson
7387273307 IB/ipath: Remove unused MDIO interface code
This code has been unused for some time, but still had leftovers
from when it was used.

Signed-off-by: Dave Olson <dave.olson@qlogic.com
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:44 -08:00
Joachim Fenkes
2ec8e66241 IB/ehca: Prevent RDMA-related connection failures on some eHCA2 hardware
Some HW revisions of eHCA2 may cause an RC connection to break if they
received RDMA Reads over that connection before.  This can be
prevented by assuring that, after the first RDMA Read, the QP receives
a new RDMA Read every few million link packets.

Include code into the driver that inserts an empty (size 0) RDMA Read
into the message stream every now and then if the consumer doesn't
post them frequently enough.

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:44 -08:00
Hoang-Nam Nguyen
bbdd267ef2 IB/ehca: Add "port connection autodetect mode"
This patch enhances ehca with a capability to "autodetect" the ports
being connected physically. In order to utilize that function the
module option nr_ports must be set to -1 (default is 2 - two
ports). This feature is experimental and will made the default later.

More detail:

If the user connects only one port to the switch, current code requires
  1) port one to be connected and
  2) module option nr_ports=1 to be given.

If autodetect is enabled, ehca will not wait at creation of the GSI QP
for the respective port to become active. Since firmware does not
accept modify_qp() while the port is down at initialization, we need
to cache all calls to modify_qp() for the SMI/GSI QP and just return a
good return code.

When a port is activated and we get a PORT_ACTIVE event, we replay the
cached modify-qp() parms and re-trigger any posted recv WRs. Only then
do we forward the PORT_ACTIVE event to registered clients.

The result of this autodetect patch is that all ports will be
accessible by the users. Depending on their respective cabling only
those ports that are connected properly will become operable. If a
user tries to modify a regular QP of a non-connected port, modify_qp()
will fail. Furthermore, ibv_devinfo should show the port state
accordingly.

Note that this patch primarily improves the loading behaviour of
ehca. If the cable is removed while the driver is operating and
plugged in again, firmware will handle that properly by sending an
appropriate async event.

Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:44 -08:00
Hoang-Nam Nguyen
b8b50e353b IB/ehca: Define array to store SMI/GSI QPs
Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:44 -08:00
Hoang-Nam Nguyen
0c86e280fe IB/ehca: Remove CQ-QP-link before destroying QP in error path of create_qp()
Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:43 -08:00
Erez Zilber
6410627eb9 IB/iser: Add change_queue_depth method
Add a .change_queue_depth handler to the scsi_host_template in the
iSER driver.  iscsi_change_queue_depth was added to iscsi_tcp in order
to solve the problem of queue depth which was too high for some
targets.  It is also applicable for iSER.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:43 -08:00
Erez Zilber
a4ef1451df IB/iser: Print information about unhandled RDMA CM events
Some RDMA CM events are not supported or not handled in iSER.
This patch adds some info (printk) for the user about them.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:43 -08:00
Olaf Kirch
a3cd7d9070 IB/fmr_pool: ib_fmr_pool_flush() should flush all dirty FMRs
When a FMR is released via ib_fmr_pool_unmap(), the FMR usually ends
up on the free_list rather than the dirty_list (because we allow a
certain number of remappings before actually requiring a flush).

However, ib_fmr_batch_release() only looks at dirty_list when flushing
out old mappings.  This means that when ib_fmr_pool_flush() is used to
force a flush of the FMR pool, some dirty FMRs that have not reached
their maximum remap count will not actually be flushed.

Fix this by flushing all FMRs that have been used at least once in
ib_fmr_batch_release().

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:43 -08:00
Olaf Kirch
a656eb758f IB/fmr_pool: Flush serial numbers can get out of sync
Normally, the serial numbers for flush requests and flushes executed
for an FMR pool should be in sync.

However, if the FMR pool flushes dirty FMRs because the
dirty_watermark was reached, we wake up the cleanup thread and let it
do its stuff.  As a side effect, the cleanup thread increments
pool->flush_ser, which leaves it one higher than pool->req_ser.  The
next time the user calls ib_flush_fmr_pool(), the cleanup thread will
be woken up, but ib_flush_fmr_pool() won't wait for the flush to
complete because flush_ser is already past req_ser.  This means the
FMRs that the user expects to be flushed may not have all been flushed
when the function returns.

Fix this by telling the cleanup thread to do work exclusively by
incrementing req_ser, and by moving the comparison of dirty_len and
dirty_watermark into ib_fmr_pool_unmap().

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
2008-01-25 14:15:42 -08:00
Roland Dreier
2fe7e6f7c9 IB/umad: Simplify and fix locking
In addition to being overly complex, the locking in user_mad.c is
broken: there were multiple reports of deadlocks and lockdep warnings.
In particular it seems that a single thread may end up trying to take
the same rwsem for reading more than once, which is explicitly
forbidden in the comments in <linux/rwsem.h>.

To solve this, we change the locking to use plain mutexes instead of
rwsems.  There is one mutex per open file, which protects the contents
of the struct ib_umad_file, including the array of agents and list of
queued packets; and there is one mutex per struct ib_umad_port, which
protects the contents, including the list of open files.  We never
hold the file mutex across calls to functions like ib_unregister_mad_agent(),
which can call back into other ib_umad code to queue a packet, and we
always hold the port mutex as long as we need to make sure that a
device is not hot-unplugged from under us.

This even makes things nicer for users of the -rt patch, since we
remove calls to downgrade_write() (which is not implemented in -rt).

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:42 -08:00
Roland Dreier
cf9542aa92 IB/ipath: Fix some sparse warnings about shadowed symbols
There are a few places in the ipath driver where a variable is
re-declared within a block where it is already in scope.  Most of these
extra declarations can simply be removed, since the variable from the
outer scope is used in a way so that it does not need to keep its
variable across the block with the re-declaration.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:42 -08:00
Roland Dreier
1d6e658e8e RDMA/cxgb3: Endianness annotation for irs field
t3_rdma_init_wr.irs is a big-endian field, so declare it as __be32.
This fixes one sparse warning.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:42 -08:00
Anton Blanchard
1a7d2dce41 IB/ehca: Use round_jiffies() for EQ polling timer
Use round_jiffies() to align ehca's 1-second timer with other timers
and potentially save power by sleeping cores for longer.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:41 -08:00
Sean Hefty
5851bb893e RDMA/cma: Override default responder_resources with user value
By default, the responder_resources parameter is set to that received
in a connection request.  The passive side may override this value
when accepting the connection.  Use the value provided by the passive
side when transitioning the QP to RTR state, rather than the value
given in the connect request.  Without this change, the RTR transition
may fail if the passive side supports fewer responder_resources than
that in the request.

For code consistency and to protect against QP destruction, restructure
overriding initiator_depth to match how responder_resources is set.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:41 -08:00
Dave Olson
1f813ca830 IB/ipath: Drop support for the original QHT7040 board
The original QHT7040 had significant performance issues so there was an
additional check in the driver for a newer serial number.  Support for
the small quantities of that board shipped has been dropped, so this
patch removes the special checks to simplify the code.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:40 -08:00
Arthur Jones
7da0498e7f IB/ipath: Add ipath_read_ireg() abstraction
Different chips have different width interrupt status registers, so add
a flag and accessor function to decide which width register read to use.

Signed-off-by: Arthur Jones <arthur.jones@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:40 -08:00
Ralph Campbell
4ea61b548b IB/ipath: Add flag and handling for chips with swapped register bug
The 6110 had a bug that caused some registers to be swapped; it was
fixed for the 7220 (and didn't affect the 6120 because it had fewer
registers).  This adds a flag and related code to handle that, and
includes some minor cleanups in the same area.

Signed-off-by:  Ralph Campbell <ralph.campbell@qlogic.com>
2008-01-25 14:15:39 -08:00
Ralph Campbell
60948a4158 IB/ipath: Port config has on-chip effects for 7220
The number of configured ports for the 7220 changes the number of eager
TIDs available per port, for all but port 0 (kernel port) which remains
constant, so add a field to give port0 count separate from the portdata
structure.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:39 -08:00
Ralph Campbell
a18e26ae44 IB/ipath: Allow more flexible user register alignments
User registers have different alignments on different chips (4KB on
older, 64KB on 7220).  Allow mapping the user registers on kernels with
page sizes up to 64K.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:39 -08:00
Dave Olson
9e2ef36b5a IB/ipath: Clean up some comments
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:38 -08:00
Ralph Campbell
3029fcc3d4 IB/ipath: Export hardware counters more consistently
Various hardware counters are exported via the ipath file system (since
it is binary data).  The old file format was very dependent on the HW
offsets for these registers.  Newer HCA chips can have different
counters at different offsets.  This patch adds a level of indirection
to make the file format consistent across HCAs.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:38 -08:00
Ralph Campbell
6c719cae0b IB/ipath: MAD performance sampling registers support
Add support for QLogic HCAs which have hardware performance sampling
registers for PortSamplesControl and PortSamplesResult MADs.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:38 -08:00
David Dillow
7aa54bd730 IB/srp: Add identifying information to log messages
When you have multiple targets, it gets really confusing when you try
to track down who did a reset when there is no identifying information
in the log message, especially when the same extension ID is mapped
through two different local IB ports.  So, add an identifier that can
be used to track back to which local IB port/remote target pair is the
one having problems.

Signed-off-by: David Dillow <dillowda@ornl.gov>
Acked-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:38 -08:00
Pradeep Satyanarayana
586a693448 IPoIB/CM: Enable SRQ support on HCAs that support fewer than 16 SG entries
Some HCAs (such as ehca2) support SRQ, but only support fewer than 16 SG
entries for SRQs.  Currently IPoIB/CM implicitly assumes all HCAs will
support 16 SG entries for SRQs (to handle a 64K MTU with 4K pages). This
patch removes that restriction by limiting the maximum MTU in connected
mode to what the maximum number of SRQ SG entries allows.

This patch addresses <https://bugs.openfabrics.org/show_bug.cgi?id=728>

Signed-off-by: Pradeep Satyanarayana <pradeeps@linux.vnet.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:37 -08:00
David Dillow
fff09a8e6e IB/srp: Enable SG list chaining
By default, the SCSI mid-layer seems to send down 512KB requests
(sg_tablesize = 256), with some requests occasionally combined. By
allowing the mid-layer to chain requests, we can easily grow to 1024KB
or larger -- I've tested 4096KB I/O requests with no problems.

I looked through the DMA paths on the hardware drivers to ensure they
could take advantage of the SG chaining, and it seems that every one
except ipath uses the system's DMA routines, which have been converted
to handle chaining.  ipath looks like it should be OK, but I have no
way to test it.

Signed-off-by: David Dillow <dillowda@ornl.gov>

[ Tested on ipath.  - Roland ]

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:37 -08:00
David Dillow
8cba207732 IB/srp: Respect target credit limit
The current SRP initiator will send requests even if it has no credits
available.  The results of sending extra requests are vendor specific,
but on some devices, overrunning credits will cost 85% of peak
performance -- e.g. 100 MB/s vs 720 MB/s.  Other devices may just drop
the requests.

This patch will tell the SCSI midlayer to queue requests if there are
fewer than two credits remaining, and will not issue a task management
request if there are no credits remaining.  The mid-layer will retry
the queued command once an outstanding command completes.

The patch also removes the unlikely() in __srp_get_tx_iu(), as it is
not at all unlikely to hit this limit under heavy load.

Signed-off-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-01-25 14:15:37 -08:00