Commit Graph

87550 Commits

Author SHA1 Message Date
Trond Myklebust
dc9d8d0481 NLM/lockd: convert __nlm_async_call to use rpc_run_task()
Peter Staubach comments:

> In the course of investigating testing failures in the locking phase of
> the Connectathon testsuite, I discovered a couple of things.  One was
> that one of the tests in the locking tests was racy when it didn't seem
> to need to be and two, that the NFS client asynchronously releases locks
> when a process is exiting.
...
> The Single UNIX Specification Version 3 specifies that:  "All locks
> associated with a file for a given process shall be removed when a file
> descriptor for that file is closed by that process or the process holding
> that file descriptor terminates.".
>
> This does not specify whether those locks must be released prior to the
> completion of the exit processing for the process or not.  However,
> general assumptions seem to be that those locks will be released.  This
> leads to more deterministic behavior under normal circumstances.

The following patch converts the NFSv2/v3 locking code to use the same
mechanism as NFSv4 for sending asynchronous RPC calls and then waiting for
them to complete. This ensures that the UNLOCK and CANCEL RPC calls will
complete even if the user interrupts the call, yet satisfies the
above request for synchronous behaviour on process exit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:39 -04:00
Trond Myklebust
5e7f37a76f NLM/lockd: Add a reference counter to struct nlm_rqst
When we replace the existing synchronous RPC calls with asynchronous calls,
the reference count will be needed in order to allow us to examine the
result of the RPC call.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:36 -04:00
Trond Myklebust
536ff0f809 NFSv4: Ensure we don't corrupt fl->fl_flags in nfs4_proc_unlck
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:33 -04:00
Trond Myklebust
4a9af59fee NLM/lockd: Ensure we don't corrupt fl->fl_flags in nlmclnt_unlock()
Also fix up nlmclnt_lock() so that it doesn't pass modified versions of
fl->fl_flags to nlmclnt_cancel() and other helpers.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:30 -04:00
Trond Myklebust
1e799b673c SUNRPC: Fix read ordering problems with req->rq_private_buf.len
We want to ensure that req->rq_private_buf.len is updated before
req->rq_received, so that call_decode() doesn't use an old value for
req->rq_rcv_buf.len.

In 'call_decode()' itself, instead of using task->tk_status (which is set
using req->rq_received) must use the actual value of
req->rq_private_buf.len when deciding whether or not the received RPC reply
is too short.

Finally ensure that we set req->rq_rcv_buf.len to zero when retrying a
request. A typo meant that we were resetting req->rq_private_buf.len in
call_decode(), and then clobbering that value with the old rq_rcv_buf.len
again in xprt_transmit().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:20 -04:00
Trond Myklebust
c1d519312d NFSv4: Only increment the sequence id if the server saw it
It is quite possible that the OPEN, CLOSE, LOCK, LOCKU,... compounds fail
before the actual stateful operation has been executed (for instance in the
PUTFH call). There is no way to tell from the overall status result which
operations were executed from the COMPOUND.

The fix is to move incrementing of the sequence id into the XDR layer,
so that we do it as we process the results from the stateful operation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:15 -04:00
Trond Myklebust
35d05778e2 NFSv4: Remove bogus call to nfs4_drop_state_owner() in _nfs4_open_expired()
There should be no need to invalidate a perfectly good state owner just
because of a stale filehandle. Doing so can cause the state recovery code
to break, since nfs4_get_renew_cred() and nfs4_get_setclientid_cred() rely
on finding active state owners.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:12 -04:00
Trond Myklebust
dbae4c73f0 NFS: Ensure that rpc_run_task() errors are propagated back to the caller
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:08 -04:00
Trond Myklebust
c9d8f89d98 NFS: Ensure that the write code cleans up properly when rpc_run_task() fails
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:05 -04:00
Trond Myklebust
fdd1e74c89 NFS: Ensure that the read code cleans up properly when rpc_run_task() fails
In the case of readpage() we need to ensure that the pages get unlocked,
and that the error is flagged.

In the case of O_DIRECT, we need to ensure that the pages are all released.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:01 -04:00
Trond Myklebust
73e3302f60 NFS: Fix nfs_wb_page() to always exit with an error or a clean page
It is possible for nfs_wb_page() to sometimes exit with 0 return value, yet
the page is left in a dirty state.
For instance in the case where the server rebooted, and the COMMIT request
failed, then all the previously "clean" pages which were cached by the
server, but were not guaranteed to have been writted out to disk,
have to be redirtied and resent to the server.
The fix is to have nfs_wb_page_priority() check that the page is clean
before it exits...

This fixes a condition that triggers the BUG_ON(PagePrivate(page)) in
nfs_create_request() when we're in the nfs_readpage() path.

Also eliminate a redundant BUG_ON(!PageLocked(page)) while we're at it. It
turns out that clear_page_dirty_for_io() has the exact same test.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:52:58 -04:00
Trond Myklebust
080a1f148d SUNRPC: Don't attempt to destroy expired RPCSEC_GSS credentials..
..and always destroy using a 'soft' RPC call. Destroying GSS credentials
isn't mandatory; the server can always cope with a few credentials not
getting destroyed in a timely fashion.

This actually fixes a hang situation. Basically, some servers will decide
that the client is crazy if it tries to destroy an RPC context for which
they have sent an RPCSEC_GSS_CREDPROBLEM, and so will refuse to talk to it
for a while.
The regression therefor probably was introduced by commit
0df7fb74fb.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:52:54 -04:00
Trond Myklebust
b6ddf64ffe SUNRPC: Fix up xprt_write_space()
The rest of the networking layer uses SOCK_ASYNC_NOSPACE to signal whether
or not we have someone waiting for buffer memory. Convert the SUNRPC layer
to use the same idiom.
Remove the unlikely()s in xs_udp_write_space and xs_tcp_write_space. In
fact, the most common case will be that there is nobody waiting for buffer
space.

SOCK_NOSPACE is there to tell the TCP layer whether or not the cwnd was
limited by the application window. Ensure that we follow the same idiom as
the rest of the networking layer here too.

Finally, ensure that we clear SOCK_ASYNC_NOSPACE once we wake up, so that
write_space() doesn't keep waking things up on xprt->pending.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:52:44 -04:00
Trond Myklebust
24b74bf0c9 SUNRPC: Fix a bug in call_decode()
call_verify() can, under certain circumstances, free the RPC slot. In that
case, our cached pointer 'req = task->tk_rqstp' is invalid. Bug was
introduced in commit 220bcc2afd (SUNRPC:
Don't call xprt_release in call refresh).

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:52:33 -04:00
Chuck Lever
0490a54a00 lockd: introduce new function to encode private argument in SM_MON requests
Clean up: refactor the encoding of the opaque 16-byte private argument in
xdr_encode_mon().  This will be updated later to support IPv6 addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:01:10 -04:00
Chuck Lever
2ca7754d4c lockd: Fix up incorrect RPC buffer size calculations.
Switch to using the new mon_id encoder function.

Now that we've refactored the encoding of SM_MON requests, we've
discovered that the pre-computed buffer length maximums are
incorrect!

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:01:07 -04:00
Chuck Lever
ea72a7f170 lockd: document use of mon_id argument in SM_MON requests
Clean up: document the argument type that xdr_encode_common() is
marshalling by introducing a new function.  The new function will replace
xdr_encode_common() in just a sec.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:01:04 -04:00
Chuck Lever
850c95fd07 lockd: refactor SM_MON my_id argument encoder
Clean up: introduce a new XDR encoder specifically for the my_id
argument of SM_MON requests.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:01:01 -04:00
Chuck Lever
4969517431 lockd: refactor SM_MON mon_name argument encoder
Clean up: introduce a new XDR encoder specifically for the mon_name
argument of SM_MON requests.  This will be updated later to support IPv6
addresses in addition to IPv4 addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:57 -04:00
Chuck Lever
099bd05f27 lockd: Ensure NSM strings aren't longer than protocol allows
Introduce a special helper function to check the length of NSM strings
before they are placed on the wire.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:54 -04:00
Chuck Lever
f34ec991ae lockd: bring a few function declarations up to date
Clean-up: replace  __inline__ and use up-to-date function declaration
conventions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:50 -04:00
Chuck Lever
eb18860e13 NLM: NLM protocol version numbers are u32
Clean up: RPC protocol version numbers are u32.  Make sure we use an
appropriate type for NLM version numbers when calling nlm_lookup_host().

Eliminates a harmless mixed sign comparison in nlm_host_lookup().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:47 -04:00
Chuck Lever
90d5b18061 NLM: LOCKD fails to load if CONFIG_SYSCTL is not set
Bruce Fields says:
"By the way, we've got another config-related nit here:

	http://bugzilla.linux-nfs.org/show_bug.cgi?id=156

You can build lockd without CONFIG_SYSCTL set, but then the module will
fail to load."

For now, disable the sysctl registration calls in lockd if CONFIG_SYSCTL
is not enabled.  This allows the kernel to build properly if PROC_FS or
SYSCTL is not enabled, but an NFS client is desired.

In the long run, we would like to be able to build the kernel with an
NFS client but without lockd.  This makes sense, for example, if you want
an NFSv4-only NFS client, as NFSv4 doesn't use NLM at all.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:44 -04:00
Chuck Lever
1e40316bc4 SUNRPC: Add a default setting for CONFIG_SUNRPC_BIND34
Most distros will want support for rpcbind protocols 3 and 4 to default off
until they have integrated user-space support for the new rpcbind daemon
which supports IPv6 RPC services.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:41 -04:00
Chuck Lever
327a299d8a SUNRPC: Update help Kconfig text
Clean up: refresh the help text for Kconfig items related to the sunrpc
module.  Remove obsolete URLs, and make the language consistent among
the options.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:38 -04:00
Chuck Lever
ecfc555a83 NFS: Always enable NFS direct I/O
Since O_DIRECT is a standard feature that is enabled in most distros,
eliminate the CONFIG_NFS_DIRECTIO build option, and change the
fs/nfs/Makefile to always build in the NFS direct I/O engine.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:34 -04:00
Chuck Lever
82d101d58a NFS: Show most mount options via nfs_show_options()
Display all mount options in /proc/mount which may be needed to reconstruct
a previous mount.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:29 -04:00
Chuck Lever
3f8400d1f1 NFS: Save the values of the "mount*=" mount options
Save the value of the mountproto= mountport= mountvers= and mountaddr=
options so that these values can be displayed later via
nfs_show_options().

This preserves the intent of the original mount options, should the file
system need to be remounted based on what's displayed in /proc/mounts.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:22 -04:00
Chuck Lever
f22d6d79fe NFS: Save the value of the "port=" mount option
During a remount based on the mount options displayed in /proc/mounts, we
want to preserve the original behavior of the mount request.  Let's save
the original setting of the "port=" mount option in the mount's nfs_server
structure.

This allows us to simplify the default behavior of port setting for NFSv4
mounts: by default, NFSv2/3 mounts first try an RPC bind to determine the
NFS server's port, unless the user specified the "port=" mount option;
Users can force the client to skip the RPC bind by explicitly specifying
"port=<value>".

NFSv4, by contrast, assumes the NFS server port is 2049 and skips the RPC
bind, unless the user specifies "port=".  Users can force an RPC bind for
NFSv4 by explicitly specifying "port=0".

I added a couple of extra comments to clarify this behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:19 -04:00
Chuck Lever
78fa701f34 NFS: Fix up data types of fields in nfs_parsed_mount_options
Clean up: make data types of fields in nfs_parsed_mount_options more
consistent with other uses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:16 -04:00
Chuck Lever
2d76743227 NFS: numeric mount parameters are unsigned
Clean up: use %u instead of %d when displaying NFS mount options.

Nit: Fix reporting of "namlen=" option in nfs_show_mount_stats.  The mount
option is called "namlen" without the "e".

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:13 -04:00
Jeff Layton
7bda2cdf48 NFS: clean up short packet handling for NFSv4 readdir
Currently, the NFS readdir decoders have a workaround for buggy servers
that send an empty readdir response with the EOF bit unset. If the
server sends a malformed response in some cases, this workaround kicks
in and just returns an empty response rather than returning a proper
error to the caller.

This patch does 3 things:

1) have malformed responses with no entries return error (-EIO)

2) preserve existing workaround for servers that send empty
   responses with the EOF marker unset.

3) Add some comments to clarify the logic in decode_readdir().

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:10 -04:00
Jeff Layton
643f81115b NFS: clean up short packet handling for NFSv3 readdir
Currently, the NFS readdir decoders have a workaround for buggy servers
that send an empty readdir response with the EOF bit unset. If the
server sends a malformed response in some cases, this workaround kicks
in and just returns an empty response rather than returning a proper
error to the caller.

This patch does 3 things:

1) have malformed responses with no entries return error (-EIO)

2) preserve existing workaround for servers that send empty
   responses with the EOF marker unset.

3) Add some comments to clarify the logic in nfs3_xdr_readdirres().

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:06 -04:00
Jeff Layton
caa02bd540 NFS: clean up short packet handling for NFSv2 readdir
Currently, the NFS readdir decoders have a workaround for buggy servers
that send an empty readdir response with the EOF bit unset. If the
server sends a malformed response in some cases, this workaround kicks
in and just returns an empty response rather than returning a proper
error to the caller.

This patch does 3 things:

1) have malformed responses with no entries return error (-EIO)

2) preserve existing workaround for servers that send empty
   responses with the EOF marker unset.

3) Add some comments to clarify the logic in nfs_xdr_readdirres().

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 18:00:03 -04:00
Fred Isaman
4af68bffac nfs: remove duplicate initializations of nfs_read_data field
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 17:59:59 -04:00
Fred
6d884e8fc8 nfs: nfs_redirty_request
Both flush functions have the same error handling routine.  Pull
it out as a function.

Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 17:59:56 -04:00
Trond Myklebust
c7c350e92a Merge branch 'hotfixes' into devel 2008-03-19 17:59:44 -04:00
Fred Isaman
f8512ad0da nfs: don't ignore return value from nfs_pageio_add_request
Ignoring the return value from nfs_pageio_add_request can cause deadlocks.

In read path:
  call nfs_pageio_add_request from readpage_async_filler
  assume at this point that there are requests already in desc, that
    can't be merged with the current request.
  so nfs_pageio_doio is fired up to clear out desc.
  assume something goes wrong in setting up the io, so desc->pg_error is set.
  This causes nfs_pageio_add_request to return 0, *WITHOUT* adding the original
    request.
  BUT, since return code is ignored, readpage_async_filler assumes it has
    been added, and does nothing further, leaving page locked.
  do_generic_mapping_read will eventually call lock_page, resulting in deadlock

In write path:
  page is marked dirty by generic_perform_write
  nfs_writepages is called
  call nfs_pageio_add_request from nfs_page_async_flush
  assume at this point that there are requests already in desc, that
    can't be merged with the current request.
  so nfs_pageio_doio is fired up to clear out desc.
  assume something goes wrong in setting up the io, so desc->pg_error is set.
  This causes nfs_page_async_flush to return 0, *WITHOUT* adding the original
    request, yet marking the request as locked (PG_BUSY) and in writeback,
    clearing dirty marks.
  The next time a write is done to the page, deadlock will result as
    nfs_write_end calls nfs_update_request

Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-19 17:59:02 -04:00
Linus Torvalds
264e3e889d Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  async_tx: avoid the async xor_zero_sum path when src_cnt > device->max_xor
  fsldma: Fix the DMA halt when using DMA_INTERRUPT async_tx transfer.
2008-03-18 21:34:48 -07:00
Alexey Starikovskiy
d7a0e1f564 Revert "ACPI: EC: Handle IRQ storm on Acer laptops"
This reverts commit 2c81ce4c9c.

It caused several new troubles (eg suspend slowdown bisected down to
this patch by Pavel Machek), so just revert it for now.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-18 21:32:24 -07:00
Linus Torvalds
2caf470363 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel:
  sched: tune multi-core idle balancing
  sched: retune wake granularity
  sched: wakeup-buddy tasks are cache-hot
  sched: improve affine wakeups
  sched, net: socket wakeups are sync
  sched: clean up wakeup balancing, code flow
  sched: clean up wakeup balancing, rename variables
  sched: clean up wakeup balancing, move wake_affine()
2008-03-18 21:27:13 -07:00
Linus Torvalds
6c3c3158a8 IDE: Make taskfile interface more robust wrt unexpected end-of-command
Now that we handle all the special commands using REQ_TYPE_ATA_TASKFILE
rather than using the old REQ_TYPE_ATA_CMD model, we need to also
emulate the lack of full taskfile data that comes with the old command
model (ie when commands are generated with the HDIO_DRIVE_CMD ioctl
rather than using the HDIO_DRIVE_TASK[FILE] ioctls).

In particular, this means that we should handle command completion the
more relaxed way that the old drive_cmd_intr() code did.  It allows
commands to finish early even if they don't use up all the data that we
thought we had for them.

This fixes a regression seen by Anders Eriksson where some SMART
commands sent by smartd would cause a boot-time system hang on his
machine because the IDE command handling code didn't realize that the
command had completed.

Tested-by: Anders Eriksson <aeriksson@fastmail.fm>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-18 21:26:24 -07:00
Linus Torvalds
d5eee40572 Merge branch 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm
* 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  slub page alloc fallback: Enable interrupts for GFP_WAIT.
2008-03-18 21:13:19 -07:00
Ingo Molnar
33b0c4217d sched: tune multi-core idle balancing
WAKE_IDLE is too agressive on multi-core CPUs with the new
wake-affine code, keep it on for SMT/HT balancing alone
(where there's no cache affinity at all between logical CPUs).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
74e3cd7f48 sched: retune wake granularity
reduce wake-up granularity for better interactivity.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
f540a6080a sched: wakeup-buddy tasks are cache-hot
Wakeup-buddy tasks are cache-hot - this makes it a bit harder
for the load-balancer to tear them apart. (but it's still possible,
if the load is sufficiently assymetric)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
4ae7d5cefd sched: improve affine wakeups
improve affine wakeups. Maintain the 'overlap' metric based on CFS's
sum_exec_runtime - which means the amount of time a task executes
after it wakes up some other task.

Use the 'overlap' for the wakeup decisions: if the 'overlap' is short,
it means there's strong workload coupling between this task and the
woken up task. If the 'overlap' is large then the workload is decoupled
and the scheduler will move them to separate CPUs more easily.

( Also slightly move the preempt_check within try_to_wake_up() - this has
  no effect on functionality but allows 'early wakeups' (for still-on-rq
  tasks) to be correctly accounted as well.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
6f3d09291b sched, net: socket wakeups are sync
'sync' wakeups are a hint towards the scheduler that (certain)
networking related wakeups likely create coupling between tasks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
f48273860e sched: clean up wakeup balancing, code flow
Clean up the code flow. No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   09b31c44e9aff8666f72773dc433e2df  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:53 +01:00
Ingo Molnar
ac192d3921 sched: clean up wakeup balancing, rename variables
rename 'cpu' to 'prev_cpu'. No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   09b31c44e9aff8666f72773dc433e2df  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-19 04:27:52 +01:00