Remove an avoidable 3ms delay on some dm-raid1 and kcopyd I/O.
It is specified that any submitted bio without BIO_RW_SYNC flag may plug the
queue (i.e. block the requests from being dispatched to the physical device).
The queue is unplugged when the caller calls blk_unplug() function. Usually, the
sequence is that someone calls submit_bh to submit IO on a buffer. The IO plugs
the queue and waits (to be possibly joined with other adjacent bios). Then, when
the caller calls wait_on_buffer(), it unplugs the queue and submits the IOs to
the disk.
This was happenning:
When doing O_SYNC writes, function fsync_buffers_list() submits a list of
bios to dm_raid1, the bios are added to dm_raid1 write queue and kmirrord is
woken up.
fsync_buffers_list() calls wait_on_buffer(). That unplugs the queue, but
there are no bios on the device queue as they are still in the dm_raid1 queue.
wait_on_buffer() starts waiting until the IO is finished.
kmirrord is scheduled, kmirrord takes bios and submits them to the devices.
The submitted bio plugs the harddisk queue but there is no one to unplug it.
(The process that called wait_on_buffer() is already sleeping.)
So there is a 3ms timeout, after which the queues on the harddisks are
unplugged and requests are processed.
This 3ms timeout meant that in certain workloads (e.g. O_SYNC, 8kb writes),
dm-raid1 is 10 times slower than md raid1.
Every time we submit something asynchronously via dm_io, we must unplug the
queue actually to send the request to the device.
This patch adds an unplug call to kmirrord - while processing requests, it keeps
the queue plugged (so that adjacent bios can be merged); when it finishes
processing all the bios, it unplugs the queue to submit the bios.
It also fixes kcopyd which has the same potential problem. All kcopyd requests
are submitted with BIO_RW_SYNC.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
This patch replaces the schedule() in the main kmirrord thread with a timer.
The schedule() could introduce an unwanted delay when work is ready to be
processed.
The code instead calls wake() when there's work to be done immediately, and
delayed_wake() after a failure to give a short delay before retrying.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove client counting code that is no longer needed.
Initialization and destruction is made globally from dm_init and dm_exit and is
not based on client counts. Initialization allocates only one empty slab cache,
so there is no negative impact from performing the initialization always,
regardless of whether some client uses kcopyd or not.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change the global mempool in kcopyd into a per-device mempool to avoid
deadlock possibilities.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove internal module reference fields from the interface.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the dm-log interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the kcopyd interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the dm-io interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Save pointer to dm_target in dm_snapshot structure.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move the dirty region log code into a separate module so
other targets can share the code.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change dm-log.c messages from "mirror log" to "dirty region log" as
a new dm target wants to share this code.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Limit the amount of memory allocated per snapshot on systems
with a large page size. (The larger default chunk size on
these systems compensates for the smaller number of pages reserved.)
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If a snapshot has a smaller chunksize than the page size the
conversion to pages currently returns 0 instead of 1, causing:
kernel BUG in mempool_resize.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
Stephen Rothwell noticed that:
Commit 2be621498d ("x86: dma-ops on highmem
fix") in Linus' tree introduced a new warning (noticed in the x86_64
allmodconfig build of linux-next):
drivers/pci/intel-iommu.c:2240: warning: initialization from incompatible pointer type
Which points at an instance of map_single that needs updating.
Fix it to the new prototype.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Fix typo in previous commit
[CIFS] Fix define for new proxy cap to match documentation
[CIFS] Fix UNC path prefix on QueryUnixPathInfo to have correct slash
[CIFS] Reserve new proxy cap for WAFS
[CIFS] Add various missing flags and defintions
[CIFS] make cifs_dfs_automount_list_static
[CIFS] Fix oops when slow oplock process races with unmount
[CIFS] Fix acl length when very short ACL being modified by chmod
[CIFS] Fix looping on reconnect to Samba when unexpected tree connect fail on reconnect
[CIFS] minor update to change log
Fix a regression in the RXKAD security module introduced in:
commit 91e916cffe
Author: Al Viro <viro@ftp.linux.org.uk>
Date: Sat Mar 29 03:08:38 2008 +0000
net/rxrpc trivial annotations
A variable was declared as a 16-bit type rather than a 32-bit type.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-with-apologies-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
This snuck in through 919ee677b6
("[SPARC64]: Add NUMA support")
Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (80 commits)
SUNRPC: Invalidate the RPCSEC_GSS session if the server dropped the request
make nfs_automount_list static
NFS: remove duplicate flags assignment from nfs_validate_mount_data
NFS - fix potential NULL pointer dereference v2
SUNRPC: Don't change the RPCSEC_GSS context on a credential that is in use
SUNRPC: Fix a race in gss_refresh_upcall()
SUNRPC: Don't disconnect more than once if retransmitting NFSv4 requests
SUNRPC: Remove the unused export of xprt_force_disconnect
SUNRPC: remove XS_SENDMSG_RETRY
SUNRPC: Protect creds against early garbage collection
NFSv4: Attempt to use machine credentials in SETCLIENTID calls
NFSv4: Reintroduce machine creds
NFSv4: Don't use cred->cr_ops->cr_name in nfs4_proc_setclientid()
nfs: fix printout of multiword bitfields
nfs: return negative error value from nfs{,4}_stat_to_errno
NLM/lockd: Ensure client locking calls use correct credentials
NFS: Remove the buggy lock-if-signalled case from do_setlk()
NLM/lockd: Fix a race when cancelling a blocking lock
NLM/lockd: Ensure that nlmclnt_cancel() returns results of the CANCEL call
NLM: Remove the signal masking in nlmclnt_proc/nlmclnt_cancel
...
* 'for-linus' of git://linux-nfs.org/~bfields/linux: (52 commits)
knfsd: clear both setuid and setgid whenever a chown is done
knfsd: get rid of imode variable in nfsd_setattr
SUNRPC: Use unsigned loop and array index in svc_init_buffer()
SUNRPC: Use unsigned index when looping over arrays
SUNRPC: Update RPC server's TCP record marker decoder
SUNRPC: RPC server still uses 2.4 method for disabling TCP Nagle
NLM: don't let lockd exit on unexpected svc_recv errors (try #2)
NFS: don't let nfs_callback_svc exit on unexpected svc_recv errors (try #2)
Use a zero sized array for raw field in struct fid
nfsd: use static memory for callback program and stats
SUNRPC: remove svc_create_thread()
nfsd: fix comment
lockd: Fix stale nlmsvc_unlink_block comment
NFSD: Strip __KERNEL__ testing from unexported header files.
sunrpc: make token header values less confusing
gss_krb5: consistently use unsigned for seqnum
NFSD: Remove NFSv4 dependency on NFSv3
SUNRPC: Remove PROC_FS dependency
NFSD: Use "depends on" for PROC_FS dependency
nfsd: move most of fh_verify to separate function
...
* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (452 commits)
V4L/DVB (7731): tuner-xc2028: fix signal strength calculus
V4L/DVB (7730): tuner-xc2028: Fix SCODE load for MTS firmwares
V4L/DVB (7729): Fix VIDIOCGAP corruption in ivtv
V4L/DVB (7728): tea5761: bugzilla #10462: tea5761 autodetection code were broken
V4L/DVB (7726): cx23885: Enable cx23417 support on the HVR1800
V4L/DVB (7725): cx23885: Add generic cx23417 hardware encoder support
V4L/DVB (7723): pvrusb2: Clean up input selection list generation in V4L interface
V4L/DVB (7722): pvrusb2: Implement FM radio support for Gotview USB2.0 DVD 2
V4L/DVB (7721): pvrusb2: Restructure cx23416 firmware loading to have a common exit point
V4L/DVB (7720): pvrusb2: Fix bad error code on cx23416 firmware load failure
V4L/DVB (7719): pvrusb2: Implement input selection enforcement
V4L/DVB (7718): pvrusb2-dvb: update Kbuild selections
V4L/DVB (7717): pvrusb2-dvb: add DVB-T support for Hauppauge pvrusb2 model 73xxx
V4L/DVB (7716): pvrusb2: clean up global functions
V4L/DVB (7715): pvrusb2: Clean out all use of __FUNCTION__
V4L/DVB (7714): pvrusb2: Fix hang on module removal
V4L/DVB (7713): pvrusb2: Implement cleaner DVB kernel thread shutdown
V4L/DVB (7712): pvrusb2: Close connect/disconnect race
V4L/DVB (7711): pvrusb2: Fix race on module unload
V4L/DVB (7710): pvrusb2: Implement critical digital streaming quirk for onair devices
...
RFC 2203 requires the server to drop the request if it believes the
RPCSEC_GSS context is out of sequence. The problem is that we have no way
on the client to know why the server dropped the request. In order to avoid
spinning forever trying to resend the request, the safe approach is
therefore to always invalidate the RPCSEC_GSS context on every major
timeout.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There are different tables for MTS firmwares. This should be taken into
account while selecting the proper firmware.
While at tuner-xc2028.h, improve some comments.
Thanks to Edward J. Sheldrake <ejs1920@yahoo.co.uk> for helping to
diagnose such troubles with PAL/I standard.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Frank Bennett reported that ivtv was causing skype to crash. With help
from one of their developers he showed it was a kernel problem.
VIDIOCGCAP copies a name into a fixed length buffer - ivtv uses names
that are too long and does not truncate them so corrupts a few bytes of
the app data area.
Possibly the names also want trimming but for now this should fix the
corruption case.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
cx23885: Enable cx23417 support on the HVR1800
Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Change how list of possible pvrusb2 inputs is generated to include
only those interfaces that make sense for the interface instance.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
These changes are required with the addition of digital television support
for the Hauppauge HVR1900 & HVR1950, the OnAir Creator and Sasem USB HDTV
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This patch contains the following cleanups:
- make the following needlessly global function static:
- pvr2_hdw_set_cur_freq()
- #if 0 the following unused global functions:
- pvr2_hdw_get_state_name()
- pvr2_hdw_get_debug_info_unlocked()
- pvr2_hdw_get_debug_info_locked()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Apparently the kernel developers no longer consider it proper
etiquette to use __FUNCTION__; everyone must instead use __func__
(even though it breaks with older compilers). And worse still, actual
effort is being expended to sweep this change throughout the kernel
source tree. Don't these people have better things to do? So...
Completely clean out all use of __FUNCTION__ from the pvrusb2 driver
(it was just in the sysfs interface). I'm not going to use __func__
either. So there.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The pvrusb2 driver was getting had by this scenario:
1. Task A calls kthread_stop() for task B.
2. Before exiting, then Task B calls kthread_stop() for task C.
The problem is, kthread_stop() wants to allocate an internal resource
to itself (i.e. acquire a lock), which won't be released until
kthread_stop() returns. But kthread_stop() won't return until task B
is dead. But task B won't die until it finishes its call to
kthread_stop() for task C, and that will block waiting on the resource
already allocated inside task A. Deadlock.
With the pvrusb2 driver, task A is the caller to pvr_exit(), task B is
the control thread run inside of pvrusb2-context.c, and task C is any
worker thread run inside of pvrusb2-hdw.c.
This problem got introduced by the previous threading setup change,
which was itself an attempt to fix a module tear-down race (which it
actually did fix). The lesson here is that a task being waited on as
part of a kthread_stop() simply cannot be allow to also issue a
kthread_stop() - or we make sure not to issue the enclosing
kthread_stop() until we know that the inner kthread_stop() has
completed first. The solution for the pvrusb2 driver is some hackish
code which changes the main control thread tear down into a two step
process. This then makes it possible to delay issuing the
kthread_stop() on the control thread until after we know that
everything has been torn down first. (And yes, we really need that
kthread_stop() because it's the only way to safely guarantee that a
module-referencing kernel thread has safely returned back out of the
module before we finally remove the module.)
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
