Commit graph

75 commits

Author SHA1 Message Date
Joe Perches
f64f9e7192 net: Move && and || to end of previous line
Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-29 16:55:45 -08:00
Eric Paris
3f378b6844 net: pass kern to net_proto_family create function
The generic __sock_create function has a kern argument which allows the
security system to make decisions based on if a socket is being created by
the kernel or by userspace.  This patch passes that flag to the
net_proto_family specific create function, so it can do the same thing.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-05 22:18:14 -08:00
Andy Grover
d521b63b27 RDS/IB+IW: Move recv processing to a tasklet
Move receive processing from event handler to a tasklet.
This should help prevent hangcheck timer from going off
when RDS is under heavy load.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:39 -07:00
Andy Grover
0514f8a9c0 RDS: Do not send congestion updates to loopback connections
This issue was discovered by HP's Pradeep and fixed in OFED
1.3, but not fixed in later versions, since the fix's implementation
was not immediately applyable to the later code. This patch should
do the trick for 1.4+ codebases.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:39 -07:00
Andy Grover
433d308dd8 RDS: Fix panic on unload
Remove explicit destruction of passive connection when destroying
active end of the connection. The passive end is also on the
device's connection list, and will thus be cleaned up properly.
Panic was caused by trying to clean it up twice.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:38 -07:00
Andy Grover
86357b19bc RDS: Fix potential race around rds_i[bw]_allocation
"At rds_ib_recv_refill_one(), it first executes atomic_read(&rds_ib_allocation)
for if-condition checking,

and then executes atomic_inc(&rds_ib_allocation) if the condition was
not satisfied.

However, if any other code which updates rds_ib_allocation executes
between these two atomic operation executions,
it seems that it may result race condition. (especially when
rds_ib_allocation + 1 == rds_ib_sysctl_max_recv_allocation)"

This patch fixes this by using atomic_inc_unless to eliminate the
possibility of allocating more than rds_ib_sysctl_max_recv_allocation
and then decrementing the count if the allocation fails. It also
makes an identical change to the iwarp transport.

Reported-by: Shin Hong <hongshin@gmail.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:38 -07:00
Andy Grover
244546f0d3 RDS: Add GET_MR_FOR_DEST sockopt
RDS currently supports a GET_MR sockopt to establish a
memory region (MR) for a chunk of memory. However, the fastreg
method ties a MR to a particular destination. The GET_MR_FOR_DEST
sockopt allows the remote machine to be specified, and thus
support for fastreg (aka FRWRs).

Note that this patch does *not* do all of this - it simply
implements the new sockopt in terms of the old one, so applications
can begin to use the new sockopt in preparation for cutover to
FRWRs.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:37 -07:00
Eric Dumazet
c720c7e838 inet: rename some inet_sock fields
In order to have better cache layouts of struct sock (separate zones
for rx/tx paths), we need this preliminary patch.

Goal is to transfert fields used at lookup time in the first
read-mostly cache line (inside struct sock_common) and move sk_refcnt
to a separate cache line (only written by rx path)

This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr,
sport and id fields. This allows a future patch to define these
fields as macros, like sk_refcnt, without name clashes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18 18:52:53 -07:00
Stephen Hemminger
ec1b4cf74c net: mark net_proto_ops as const
All usages of structure net_proto_ops should be declared const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07 01:10:46 -07:00
David S. Miller
b7058842c9 net: Make setsockopt() optlen be unsigned.
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30 16:12:20 -07:00
Linus Torvalds
f205ce83a7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (66 commits)
  be2net: fix some cmds to use mccq instead of mbox
  atl1e: fix 2.6.31-git4 -- ATL1E 0000:03:00.0: DMA-API: device driver frees DMA
  pkt_sched: Fix qstats.qlen updating in dump_stats
  ipv6: Log the affected address when DAD failure occurs
  wl12xx: Fix print_mac() conversion.
  af_iucv: fix race when queueing skbs on the backlog queue
  af_iucv: do not call iucv_sock_kill() twice
  af_iucv: handle non-accepted sockets after resuming from suspend
  af_iucv: fix race in __iucv_sock_wait()
  iucv: use correct output register in iucv_query_maxconn()
  iucv: fix iucv_buffer_cpumask check when calling IUCV functions
  iucv: suspend/resume error msg for left over pathes
  wl12xx: switch to %pM to print the mac address
  b44: the poll handler b44_poll must not enable IRQ unconditionally
  ipv6: Ignore route option with ROUTER_PREF_INVALID
  bonding: make ab_arp select active slaves as other modes
  cfg80211: fix SME connect
  rc80211_minstrel: fix contention window calculation
  ssb/sdio: fix printk format warnings
  p54usb: add Zcomax XG-705A usbid
  ...
2009-09-17 20:53:52 -07:00
Linus Torvalds
ada3fa1505 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15 09:39:44 -07:00
Alexey Dobriyan
5708e868dc net: constify remaining proto_ops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14 17:03:09 -07:00
Andy Grover
f2c449320d RDS: Add a debug message suggesting to load transport modules
Now that RDS transports are no longer compiled-in to RDS core,
there is now the possibility that they will not be loaded. This
adds a helpful suggestion when rds_bind() fails to find a transport.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:13:14 -07:00
Andy Grover
335776bd69 RDS: Track transports via an array, not a list
Now that transports can be loaded in arbitrary order,
it is important for rds_trans_get_preferred() to look
for them in a particular order, instead of walking the list
until it finds a transport that works for a given address.
Now, each transport registers for a specific transport slot,
and these are ordered so that preferred transports come first,
and then if they are not loaded, other transports are queried.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:13:12 -07:00
Andy Grover
40d866095d RDS: Modularize RDMA and TCP transports
Enable the building of transports as modules.

Also, improve consistency of Kconfig messages in relation to other
protocols, and move build dependency on IB from the RDS core code
to the rds_rdma module.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:13:09 -07:00
Andy Grover
616b757ae1 RDS: Export symbols from core RDS
Now that rdma and tcp transports will be modularized,
we need to export a number of functions so they can call them.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:13:07 -07:00
Andy Grover
70041088e3 RDS: Add TCP transport to RDS
This code allows RDS to be tunneled over a TCP connection.

RDMA operations are disabled when using TCP transport,
but this frees RDS from the IB/RDMA stack dependency, and allows
it to be used with standard Ethernet adapters, or in a VM.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:13:02 -07:00
Julia Lawall
3d7ddd540b net/rds: Use AF_INET for sin_family field
Elsewhere the sin_family field holds a value with a name of the form
AF_..., so it seems reasonable to do so here as well.  Also the values of
PF_INET and AF_INET are the same.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
struct sockaddr_in sip;
@@

(
sip.sin_family ==
- PF_INET
+ AF_INET
|
sip.sin_family !=
- PF_INET
+ AF_INET
|
sip.sin_family =
- PF_INET
+ AF_INET
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-05 20:30:13 -07:00
Jan Engelhardt
36cbd3dcc1 net: mark read-only arrays as const
String literals are constant, and usually, we can also tag the array
of pointers const too, moving it to the .rodata section.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-05 10:42:58 -07:00
Andy Grover
cb24405e67 RDS: Refactor end of __conn_create for readability
Add a comment for what's going on. Remove negative logic.
I find this much easier to understand quickly, although
there are a few lines duplicated.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:17 -07:00
Andy Grover
ed9e352a35 RDS/IW: Remove dead code
In iWARP code, node_type will always be RNIC

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:15 -07:00
Andy Grover
404bb72a56 RDS/IW: Remove page_shift variable from iwarp transport
The existing code treated page_shift as a variable, when in fact we
always want to have the fastreg page size be the same as the arch's
page size -- and it is, so this doesn't need to be a variable.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:14 -07:00
Andy Grover
a870d62726 RDS/IB: Always use PAGE_SIZE for FMR page size
While FMRs allow significant flexibility in what size of pages they can use,
we really just want FMR pages to match CPU page size. Roland says we can
count on this always being supported, so this simplifies things.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:13 -07:00
Andy Grover
edacaeae52 RDS: Fix completion notifications on blocking sockets
Completion or congestion notifications were not being checked
if the socket went to sleep. This patch fixes that.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:12 -07:00
Andy Grover
fdf6e6b4af RDS/IB: Drop connection when a fatal QP event is received
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:11 -07:00
Andy Grover
68cb01c1ba RDS/IB: Disable flow control in sysctl and explain why
Backwards compatibility with rds 3.0 causes protocol-
based flow control to be disabled as a side-effect.

I don't want to pull out FC support from the IB transport
but I do want to document and keep the sysctl consistent
if possible.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:10 -07:00
Andy Grover
e11d912a7d RDS/IB: Move tx/rx ring init and refill to later
Since RDS 3.0 and 3.1 have different packet formats,
we need to wait until after protocol negotiation
is complete to layout the rx buffers.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:08 -07:00
Andy Grover
9099707ded RDS: Don't set c_version in __rds_conn_create()
Protocol negotiation is logically a property of the
transports, so rds core need not set it.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:08 -07:00
Andy Grover
597ddd50e1 RDS/IB: Rename byte_len to data_len to enhance readability
Of course len is in bytes. Calling it data_len hopefully indicates
a little better what the variable is actually for.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:07 -07:00
Andy Grover
92c330b9e9 RDS/RDMA: Fix cut-n-paste errors in printks in rdma_transport.c
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:05 -07:00
Andy Grover
8dacd57e7e RDS/IB: Fix printk to indicate remote IP, not local
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:04 -07:00
Andy Grover
02a6a2592e RDS/IB: Handle connections using RDS 3.0 wire protocol
The big differences between RDS 3.0 and 3.1 are protocol-level
flow control, and with 3.1 the header is in front of the data. The header
always ends up in the header buffer, and the data goes in the data page.

In 3.0 our "header" is a trailer, and will end up either in the data
page, the header buffer, or split across the two. Since 3.1 is backwards-
compatible with 3.0, we need to continue to support these cases. This
patch does that -- if using RDS 3.0 wire protocol, it will copy the header
from wherever it ended up into the header buffer.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:03 -07:00
Andy Grover
9ddbcfa098 RDS/IB: Improve RDS protocol version checking
RDS on IB uses privdata to do protocol version negotiation. Apparently
the IB stack will return a larger privdata buffer than the struct we were
expecting. Just to be extra-sure, this patch adds some checks in this area.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:02 -07:00
Andy Grover
3ba23ade46 RDS: Set retry_count to 2 and make modifiable via modparam
This will be default cause IB connections to failover faster,
but allow a longer retry count to be used if desired.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:01 -07:00
Tejun Heo
b9bf3121af percpu: use DEFINE_PER_CPU_SHARED_ALIGNED()
There are a few places where ___cacheline_aligned* is used with
DEFINE_PER_CPU().  Use DEFINE_PER_CPU_SHARED_ALIGNED() instead.

DEFINE_PER_CPU_SHARED_ALIGNED() applies alignment only on SMPs.  While
all other converted places used _in_smp variant or only get compiled
for SMP, net/rds used unconditional ____cacheline_aligned.  I don't
see any reason these data structures should be aligned on UP and thus
converted together.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Grover <andy.grover@oracle.com>
2009-06-24 15:13:47 +09:00
David S. Miller
bb803cfbec Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/scsi/fcoe/fcoe.c
2009-05-18 21:08:20 -07:00
David Howells
9b8de7479d FRV: Fix the section attribute on UP DECLARE_PER_CPU()
In non-SMP mode, the variable section attribute specified by DECLARE_PER_CPU()
does not agree with that specified by DEFINE_PER_CPU().  This means that
architectures that have a small data section references relative to a base
register may throw up linkage errors due to too great a displacement between
where the base register points and the per-CPU variable.

On FRV, the .h declaration says that the variable is in the .sdata section, but
the .c definition says it's actually in the .data section.  The linker throws
up the following errors:

kernel/built-in.o: In function `release_task':
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o

To fix this, DECLARE_PER_CPU() should simply apply the same section attribute
as does DEFINE_PER_CPU().  However, this is made slightly more complex by
virtue of the fact that there are several variants on DEFINE, so these need to
be matched by variants on DECLARE.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-21 19:39:59 -07:00
Dan Carpenter
94713bab64 ERR_PTR() dereference in net/rds/ib.c
rdma_create_id() doesn't return NULL, only ERR_PTR().

Found by smatch (http://repo.or.cz/w/smatch.git).  Compile tested.

regards,
dan carpenter

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:22 -07:00
Dan Carpenter
5d57eeb52a ERR_PTR() dereference in net/rds/iw.c
rdma_create_id() returns ERR_PTR() not null.

Found by smatch (http://repo.or.cz/w/smatch.git).  Compile tested.

regards,
dan carpenter

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:22 -07:00
Wei Yongjun
05a178ecdc rds: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
Use kmem_cache_zalloc instead of kmem_cache_alloc/memset.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:21 -07:00
Huang Weiyi
9c56a84478 RDS: remove unused #include <version.h>
Remove unused #include <version.h> in net/rds/af_rds.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:20 -07:00
Andy Grover
830eb7d56c RDS: use get_user_pages_fast()
Use the new function that is simpler and faster.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:20 -07:00
Andy Grover
49f6969141 RDS: Establish connection before parsing CMSGs
The first message to a remote node should prompt a new connection.
Even an RDMA op via CMSG. Therefore move CMSG parsing to after
connection establishment.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:19 -07:00
Andy Grover
7acd4a794c RDS: Fix ordering in a conditional
Putting the constant first is a supposed "best practice" that actually makes
the code harder to read.

Thanks to Roland Dreier for finding a bug in this "simple, obviously correct"
patch.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:18 -07:00
Steve Wise
7b70d0336d RDS/IW+IB: Allow max credit advertise window.
Fix hack that restricts the credit advertisement to 127.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:17 -07:00
Steve Wise
d39e0602bb RDS/IW+IB: Set the RDS_LL_SEND_FULL bit when we're throttled.
The RDS_LL_SEND_FULL bit should be set when we stop transmitted due to
flow control.  Otherwise the send worker will keep trying as opposed to
sleeping until we unthrottle.  Saves CPU.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:16 -07:00
Andy Grover
11bc9421da RDS: Correct some iw references in rdma_transport.c
Had some lingering instances of _iw_ variable names from when
the listen code was centralized into rdma_transport.c

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:15 -07:00
Steve Wise
5cd2fe6d54 RDS/IW+IB: Set recv ring low water mark to 1/2 full.
Currently the recv ring low water mark is 1/4 the depth.  Performance
measurements show that this limits iWARP throughput by flow controlling
the rds-stress senders.  Setting it to 1/2 seems to max the T3
performance.  I tried even higher levels but that didn't help and it
started to increase the rds thread cpu utilization.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:14 -07:00
Andy Grover
8cbd9606a6 RDS: Use spinlock to protect 64b value update on 32b archs
We have a 64bit value that needs to be set atomically.
This is easy and quick on all 64bit archs, and can also be done
on x86/32 with set_64bit() (uses cmpxchg8b). However other
32b archs don't have this.

I actually changed this to the current state in preparation for
mainline because the old way (using a spinlock on 32b) resulted in
unsightly #ifdefs in the code. But obviously, being correct takes
precedence.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02 00:52:22 -07:00