19 Nov, 2011
1 commit
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Change the linked lists to rb_tree's in the rsb
hash table to speed up searches. Slow rsb searches
were having a large impact on gfs2 performance due
to the large number of dlm locks gfs2 uses.Signed-off-by: Bob Peterson
Signed-off-by: David Teigland
16 Jul, 2011
1 commit
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Instead of creating our own kthread (dlm_astd) to deliver
callbacks for all lockspaces, use a per-lockspace workqueue
to deliver the callbacks. This eliminates complications and
slowdowns from many lockspaces sharing the same thread.Signed-off-by: David Teigland
15 Jul, 2011
1 commit
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gfs2 recently began using this feature heavily,
creating more debug output than we want to see.Signed-off-by: David Teigland
13 Jul, 2011
1 commit
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By pre-allocating rsb structs before searching the hash
table, they can be inserted immediately. This avoids
always having to repeat the search when adding the struct
to hash list.This also adds space to the rsb struct for a max resource
name, so an rsb allocation can be used by any request.
The constant size also allows us to finally use a slab
for the rsb structs.Signed-off-by: David Teigland
11 Jul, 2011
3 commits
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This is simpler and quicker than the hash table, and
avoids needing to search the hash list for every new
lkid to check if it's used.Signed-off-by: David Teigland
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The gfp and size args were switched.
Signed-off-by: David Teigland
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In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
issues:1) There's no need to test the return value of the allocation and do a
memset if is succeedes. Just use kzalloc() to obtain zeroed memory.2) Since kfree() handles NULL pointers gracefully, the test of
'warned' against NULL before the kfree() after the loop is completely
pointless. Remove it.3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to
Dr. David Alan Gilbert for pointing this out.Signed-off-by: Jesper Juhl
Signed-off-by: David Teigland
25 May, 2011
1 commit
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
dlm: make plock operation killable
dlm: remove shared message stub for recovery
dlm: delayed reply message warning
dlm: Remove superfluous call to recalc_sigpending()
05 Apr, 2011
1 commit
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kmalloc a stub message struct during recovery instead of sharing the
struct in the lockspace. This leaves the lockspace stub_ms only for
faking downconvert replies, where it is never modified and sharing
is not a problem.Also improve the debug messages in the same recovery function.
Signed-off-by: David Teigland
02 Apr, 2011
1 commit
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Add an option (disabled by default) to print a warning message
when a lock has been waiting a configurable amount of time for
a reply message from another node. This is mainly for debugging.Signed-off-by: David Teigland
31 Mar, 2011
1 commit
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
11 Mar, 2011
1 commit
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Change how callbacks are recorded for locks. Previously, information
about multiple callbacks was combined into a couple of variables that
indicated what the end result should be. In some situations, we
could not tell from this combined state what the exact sequence of
callbacks were, and would end up either delivering the callbacks in
the wrong order, or suppress redundant callbacks incorrectly. This
new approach records all the data for each callback, leaving no
uncertainty about what needs to be delivered.Signed-off-by: David Teigland
03 Sep, 2010
1 commit
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When converting a lock, an lkb is in the granted state and also being used
to request a new state. In the case that the conversion was a "try 1cb"
type which has failed, and if the new state was incompatible with the old
state, a callback was being generated to the requesting node. This is
incorrect as callbacks should only be sent to all the other nodes holding
blocking locks. The requesting node should receive the normal (failed)
response to its "try 1cb" conversion request only.This was discovered while debugging a performance problem on GFS2, however
this fix also speeds up GFS as well. In the GFS2 case the performance gain
is over 10x for cases of write activity to an inode whose glock is cached
on another, idle (wrt that glock) node.(comment added, dct)
Signed-off-by: Steven Whitehouse
Tested-by: Abhijith Das
Signed-off-by: David Teigland
01 May, 2010
1 commit
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Smatch complains because "lkb" is never NULL. Looking at it, the original
code actually adds the new element to the end of the list fine, so we can
just get rid of the if condition. This code is four years old and no one
has complained so it must work.Signed-off-by: Dan Carpenter
Signed-off-by: David Teigland
30 Mar, 2010
1 commit
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…it slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
27 Feb, 2010
2 commits
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The bast mode that appears in the debugfs output should be
useful on both master and process nodes. lkb_highbast is
currently printed, and is only useful on the master node.
lkb_bastmode is only useful on the process node. This
patch sets lkb_bastmode on the master node as well, and
uses that value in the debugfs print.Signed-off-by: David Teigland
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When the lock master processes a successful operation (request,
convert, cancel, or unlock), it will process the effects of the
change before sending the reply for the operation. The "effects"
of the operation are:- blocking callbacks (basts) for any newly granted locks
- waiting or converting locks that can now be grantedThe cast is queued on the local node when the reply from the lock
master is received. This means that a lock holder can receive a
bast for a lock mode that is doesn't yet know has been granted.Signed-off-by: David Teigland
25 Feb, 2010
1 commit
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When both blocking and completion callbacks are queued for lock,
the dlm would always deliver the completion callback (cast) first.
In some cases the blocking callback (bast) is queued before the
cast, though, and should be delivered first. This patch keeps
track of the order in which they were queued and delivers them
in that order.This patch also keeps track of the granted mode in the last cast
and eliminates the following bast if the bast mode is compatible
with the preceding cast mode. This happens when a remotely mastered
lock is demoted, e.g. EX->NL, in which case the local node queues
a cast immediately after sending the demote message. In this way
a cast can be queued for a mode, e.g. NL, that makes an in-transit
bast extraneous.Signed-off-by: David Teigland
01 Dec, 2009
1 commit
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Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
ls_allocation would be GFP_KERNEL for userland lockspaces
and GFP_NOFS for file system lockspaces.It was discovered that any lockspaces on the system can
affect all others by triggering memory reclaim in the
file system which could in turn call back into the dlm
to acquire locks, deadlocking dlm threads that were
shared by all lockspaces, like dlm_recv.Signed-off-by: David Teigland
18 Jun, 2009
1 commit
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CC [M] fs/dlm/lock.o
fs/dlm/lock.c: In function ‘find_rsb’:
fs/dlm/lock.c:438: warning: ‘r’ may be used uninitialized in this functionSince r is used on the error path to set r_ret, set it to NULL.
Signed-off-by: Steven Whitehouse
Signed-off-by: David Teigland
12 Mar, 2009
2 commits
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Return immediately from dlm_unlock(CANCEL) if the lock is
granted and not being converted; there's nothing to cancel.Signed-off-by: David Teigland
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When a conversion completes successfully and finds that a cancel
of the convert is still in progress (which is now a moot point),
preemptively clear the state associated with outstanding cancel.
That state could cause a subsequent conversion to be ignored.Also, improve the consistency and content of error and debug
messages in this area.Signed-off-by: David Teigland
09 Jan, 2009
1 commit
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The rwlock is almost always used in write mode, so there's no reason
to not use a spinlock instead.Signed-off-by: David Teigland
24 Dec, 2008
3 commits
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Record the time the latest blocking callback was queued for
a lock. This will be used for debugging in combination with
lock queue timestamp changes in the previous patch.Signed-off-by: David Teigland
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Use ktime instead of jiffies for timestamping lkb's. Also stamp the
time on every lkb whenever it's added to a resource queue, instead of
just stamping locks subject to timeouts. This will allow us to use
timestamps more widely for debugging all locks.Signed-off-by: David Teigland
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The lkb bastmode value is set in the context of processing the
lock, and read by the dlm_astd thread. Because it's accessed
in these two separate contexts, the writing/reading ought to
be done under a lock. This is simple to do by setting it and
reading it when the lkb is added to and removed from dlm_astd's
callback list which is properly locked.Signed-off-by: David Teigland
15 Jul, 2008
2 commits
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gcc 4.3.0 correctly emits the following warning.
search_rsb_list does not *r_ret if no dlm_rsb is found
and _search_rsb may pass the uninitialized value upstream
on the error path when both calls to search_rsb_list
return non-zero error.The fix sets *r_ret to NULL on search_rsb_list's not-found path.
Signed-off-by: Benny Halevy
Signed-off-by: David Teigland -
The fix in commit 3650925893469ccb03dbcc6a440c5d363350f591 was addressing
the case of a granted PR lock with waiting PR and CW locks. It's a
special case that requires forcing a CW bast. However, that forced CW
bast was incorrectly applying to a second condition where the granted
lock was CW. So, the holder of a CW lock could receive an extraneous CW
bast instead of a PR bast. This fix narrows the original special case to
what was intended.Signed-off-by: David Teigland
22 Apr, 2008
2 commits
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When a NOQUEUE request fails, the rsb res_master field is unnecessarily
reset to -1, instead of leaving the valid master setting in place. We
want to save the looked-up master values while the rsb is on the "toss
list" so that another lookup can be avoided if the rsb is soon reused.
The fix is to simply leave res_master value alone.Signed-off-by: David Teigland
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dlm_print_rsb() can now become static.
Signed-off-by: Adrian Bunk
Signed-off-by: David Teigland
07 Feb, 2008
1 commit
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Put lkb_astparam in a union with a dlm_user_args pointer to
eliminate a lot of type casting.Signed-off-by: David Teigland
06 Feb, 2008
1 commit
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Use proper types for ast and bast functions, and use
consistent type for ast param.Signed-off-by: David Teigland
04 Feb, 2008
7 commits
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Signed-off-by: Al Viro
Signed-off-by: David Teigland -
We *can* get there from receive_request() and dlm_recover_master_copy()
with namelen too large if incoming request is invalid; BUG() from
DLM_ASSERT() in allocate_rsb() is a bit excessive reaction to that
and in case of dlm_recover_master_copy() we would actually oops before
that while calculating hash of up to 64Kb worth of data - with data
actually being 64 _bytes_ in kmalloc()'ed struct.Signed-off-by: Al Viro
Signed-off-by: David Teigland -
Signed-off-by: Al Viro
Signed-off-by: David Teigland -
Signed-off-by: Al Viro
Signed-off-by: David Teigland -
Signed-off-by: Al Viro
Signed-off-by: David Teigland -
* check that length is large enough to cover the non-variable part of message or
rcom resp. (after checking that it's large enough to cover the header, of
course).* kill more pointless casts
Signed-off-by: Al Viro
Signed-off-by: David Teigland -
a) don't cast the pointer to dlm_header *, we use it as dlm_message *
anyway.
b) we copy the message into a queue element, then pass the pointer to
copy to dlm_receive_message_saved(); declare it properly to make sure
that we have the right alignment.Signed-off-by: Al Viro
Signed-off-by: David Teigland
31 Jan, 2008
1 commit
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To prevent the master of an rsb from changing rapidly, an unused rsb is kept
on the "toss list" for a period of time to be reused. The toss list was
being cleared completely for each recovery, which is unnecessary. Much of
the benefit of the toss list can be maintained if nodes keep rsb's in their
toss list that they are the master of. These rsb's need to be included
when the resource directory is rebuilt during recovery.Signed-off-by: David Teigland