urcu.git
12 years agoUpdate gitignore
Alexandre Montplaisir [Fri, 6 Jan 2012 15:36:01 +0000 (10:36 -0500)] 
Update gitignore

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoreadme: state correct GCC dependency for ARM
Gerlando Falauto [Wed, 21 Dec 2011 14:50:38 +0000 (09:50 -0500)] 
readme: state correct GCC dependency for ARM

If you are trying to compile liburcu for ARM and get errors like:

/usr/local/include/urcu/uatomic/generic.h:180: undefined reference to
`__sync_add_and_fetch_4'
usr/local/lib/liburcu-common.so: undefined reference to
`__sync_lock_test_and_set_4'
/usr/local/lib/liburcu.so: undefined reference to
`__sync_or_and_fetch_4'

please upgrade your GCC to 4.4.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoVersion 0.6.7 v0.6.7
Mathieu Desnoyers [Tue, 13 Dec 2011 02:35:45 +0000 (21:35 -0500)] 
Version 0.6.7

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoAdd compat file for test urcu wfs
Mathieu Desnoyers [Thu, 8 Dec 2011 21:16:46 +0000 (16:16 -0500)] 
Add compat file for test urcu wfs

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoAdd missing compat file for wfq test
Mathieu Desnoyers [Thu, 8 Dec 2011 21:14:21 +0000 (16:14 -0500)] 
Add missing compat file for wfq test

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agourcu-bp: no need for weak attribute
Mathieu Desnoyers [Thu, 8 Dec 2011 13:28:01 +0000 (08:28 -0500)] 
urcu-bp: no need for weak attribute

We should do this within the user (e.g. liblttng-ust), not within the
urcu-bp library.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agohlist.h: Add missing stddef.h include for NULL
Mathieu Desnoyers [Mon, 5 Dec 2011 23:41:29 +0000 (18:41 -0500)] 
hlist.h: Add missing stddef.h include for NULL

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agocall_rcu: Add missing call_rcu_before_fork and call_rcu_after_fork_parent declarations
Mathieu Desnoyers [Mon, 5 Dec 2011 20:49:57 +0000 (15:49 -0500)] 
call_rcu: Add missing call_rcu_before_fork and call_rcu_after_fork_parent declarations

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoDescribe autotools/libtool/automake version dependency
Mathieu Desnoyers [Thu, 1 Dec 2011 15:40:31 +0000 (10:40 -0500)] 
Describe autotools/libtool/automake version dependency

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoRemove m4_ifdef for AC_PROG_LIBTOOL (deprecated)
Mathieu Desnoyers [Thu, 1 Dec 2011 15:18:12 +0000 (10:18 -0500)] 
Remove m4_ifdef for AC_PROG_LIBTOOL (deprecated)

This trick does not seem to work anyway.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoSupport older autotools
Mathieu Desnoyers [Wed, 30 Nov 2011 14:03:10 +0000 (09:03 -0500)] 
Support older autotools

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoApply autoupdate to configure.ac
Mathieu Desnoyers [Tue, 29 Nov 2011 20:30:26 +0000 (15:30 -0500)] 
Apply autoupdate to configure.ac

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoFix build for amd64 environment (for FreeBSD 8.2)
Mathieu Desnoyers [Mon, 28 Nov 2011 19:28:29 +0000 (14:28 -0500)] 
Fix build for amd64 environment (for FreeBSD 8.2)

Signed-off-by: David Goulet <dgoulet@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agoAdd missing rcu_dereference_sym_bp
Mathieu Desnoyers [Sun, 27 Nov 2011 08:58:52 +0000 (08:58 +0000)] 
Add missing rcu_dereference_sym_bp

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 years agourcu-bp: allow weak linking
Mathieu Desnoyers [Sun, 27 Nov 2011 00:41:09 +0000 (00:41 +0000)] 
urcu-bp: allow weak linking

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoInstall test scripts in the dist tarball
Alexandre Montplaisir [Tue, 22 Nov 2011 17:02:29 +0000 (18:02 +0100)] 
Install test scripts in the dist tarball

Fix for http://lttng.org/issue/250
Allows running `make check' when installing from the tarball

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoVersion 0.6.6 v0.6.6
Mathieu Desnoyers [Thu, 3 Nov 2011 16:49:07 +0000 (12:49 -0400)] 
Version 0.6.6

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoqsbr vs call_rcu : remove exit assertion
Mathieu Desnoyers [Wed, 14 Sep 2011 17:36:12 +0000 (13:36 -0400)] 
qsbr vs call_rcu : remove exit assertion

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoRename likely/unlikely to caa_likely/caa_unlikely
Mathieu Desnoyers [Tue, 1 Nov 2011 23:58:52 +0000 (19:58 -0400)] 
Rename likely/unlikely to caa_likely/caa_unlikely

This fixes namespace conflicts.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoReinsert missing test_urcu_*.c files (missing in rename)
Mathieu Desnoyers [Sat, 15 Oct 2011 14:08:46 +0000 (09:08 -0500)] 
Reinsert missing test_urcu_*.c files (missing in rename)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agorename test_qsbr to test_urcu_qsbr
Lai Jiangshan [Fri, 14 Oct 2011 13:46:30 +0000 (08:46 -0500)] 
rename test_qsbr to test_urcu_qsbr

[ edit by Mathieu Desnoyers: update runtests*.sh scripts accordingly ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-pointer: fix rcu_set_pointer unset return value
Mathieu Desnoyers [Wed, 5 Oct 2011 02:01:50 +0000 (22:01 -0400)] 
urcu-pointer: fix rcu_set_pointer unset return value

The problem only affected non-_LGPL_SOURCE configs.

Reported-by: Stephen Hemminger <shemminger@vyatta.com>
Fix-proposed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoEnhance API.txt documentation, add to Makefile as EXTRA_DIST
Mathieu Desnoyers [Sun, 2 Oct 2011 16:53:44 +0000 (12:53 -0400)] 
Enhance API.txt documentation, add to Makefile as EXTRA_DIST

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoVersion 0.6.5 v0.6.5
Mathieu Desnoyers [Thu, 29 Sep 2011 22:15:42 +0000 (18:15 -0400)] 
Version 0.6.5

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocall_rcu: Document call_rcu requirements
Mathieu Desnoyers [Thu, 29 Sep 2011 21:40:01 +0000 (17:40 -0400)] 
call_rcu: Document call_rcu requirements

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocall_rcu: fix error handling of malloc error
Mathieu Desnoyers [Thu, 29 Sep 2011 21:17:05 +0000 (17:17 -0400)] 
call_rcu: fix error handling of malloc error

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu call_rcu: Use RCU read-side protection for per-cpu call_rcu data
Mathieu Desnoyers [Thu, 29 Sep 2011 21:13:48 +0000 (17:13 -0400)] 
urcu call_rcu: Use RCU read-side protection for per-cpu call_rcu data

A concurrent get_cpu_call_rcu_data(), called by get_call_rcu_data(),
could dereference this pointer without holding any mutex. So this
situation would happen if we have a concurrent call_rcu() executing
while we do the create_all_cpu_call_rcu_data().

I think we would need to put a rcu_dereference() around
per_cpu_call_rcu_data read within get_cpu_call_rcu_data() too.
per_cpu_call_rcu_data should be done with rcu_set_pointer.

Also, a rcu read-side critical section would be required around any
usage of per_cpu_call_rcu_data, and the action of tearing down the
per-cpu data would require to wait for a quiescent state. So we would
basically require that the call_rcu users need to be registered as
RCU reader threads.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu,call_rcu: Cleanup call_rcu_data pointers before use in child
Lai Jiangshan [Thu, 29 Sep 2011 19:56:43 +0000 (15:56 -0400)] 
urcu,call_rcu: Cleanup call_rcu_data pointers before use in child

[ Edit by Mathieu Desnoyers: create maxcpus_reset to handle cases where
  maxcpus is 0 and -1, depending on the configuration. ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu,call_rcu: avoid create call_rcu_data for child when unneed
Lai Jiangshan [Thu, 29 Sep 2011 17:55:11 +0000 (13:55 -0400)] 
urcu,call_rcu: avoid create call_rcu_data for child when unneed

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu,defer_rcu: Make defer_rcu encoding more compact for marker
Lai Jiangshan [Thu, 29 Sep 2011 17:47:13 +0000 (13:47 -0400)] 
urcu,defer_rcu: Make defer_rcu encoding more compact for marker

When the function changes (and the function is aligned), and only the
data is the marker, we can get away with using only 2 pointers rather
than 3.

[ Edit by Mathieu Desnoyers: patch cleanup, changelog updates ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu_defer: Use cancellation flag instead of pthread_cancel()
Mathieu Desnoyers [Thu, 29 Sep 2011 17:28:04 +0000 (13:28 -0400)] 
urcu_defer: Use cancellation flag instead of pthread_cancel()

- Provides better control over cancellation point location.
- Set the futex to 0 before exiting the defer thread.

This patch combines and enhances patches from Lai Jiangshan:
  urcu,defer_rcu: fix missing respond to a cancellation request
  urcu,defer_rcu: Avoid thread exit unexpected

Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu,call_rcu: protects call_rcu_data_list when remove node
Lai Jiangshan [Thu, 29 Sep 2011 17:04:12 +0000 (13:04 -0400)] 
urcu,call_rcu: protects call_rcu_data_list when remove node

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoCreate default call rcu data upon per-cpu call-rcu teardown
Mathieu Desnoyers [Wed, 28 Sep 2011 20:03:13 +0000 (16:03 -0400)] 
Create default call rcu data upon per-cpu call-rcu teardown

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agopowerpc: use __NO_LWSYNC__ check to use appropriate lwsync/sync opcode
Mathieu Desnoyers [Thu, 22 Sep 2011 15:00:14 +0000 (11:00 -0400)] 
powerpc: use __NO_LWSYNC__ check to use appropriate lwsync/sync opcode

We already used it in uatomic code, move it to arch ppc.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocmm: provide lightweight smp_rmb/smp_wmb on PPC
Paolo Bonzini [Thu, 22 Sep 2011 09:12:44 +0000 (05:12 -0400)] 
cmm: provide lightweight smp_rmb/smp_wmb on PPC

lwsync orders loads in cacheable memory with respect to other loads,
and stores in cacheable memory with respect to other stores.  Use it
to implement smp_rmb/smp_wmb.

The heavy-weight sync is still used for the "full" rmb/wmb operations,
as well as for smp_mb.

[ Edit by Mathieu Desnoyers: rephrased the comments around the memory
  barriers. ]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoatomic: provide seq_cst semantics on powerpc
Mathieu Desnoyers [Thu, 22 Sep 2011 00:25:20 +0000 (20:25 -0400)] 
atomic: provide seq_cst semantics on powerpc

We provide sequential consistency semantic over all architectures for
cmpxchg and add_return family of primitives, but the powerpc
implementation does not match that.

Change the isync after the atomic primitives to sync, and explain the
scheme.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoavoid leaking crdp for failed path
Lai Jiangshan [Thu, 15 Sep 2011 15:24:03 +0000 (11:24 -0400)] 
avoid leaking crdp for failed path

[ Comment: now that set_cpu_call_rcu_data() is not racy and detects
  overwrites, we can effectively trust its return value and free the
  crdp if already set. ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoReturn -EEXIST when the old cpu call_rcu_data has not been removed
Lai Jiangshan [Thu, 15 Sep 2011 15:22:03 +0000 (11:22 -0400)] 
Return -EEXIST when the old cpu call_rcu_data has not been removed

To make it matches the comments.

It is the caller's responsibility to use
set_cpu_call_rcu_data(cpu, NULL) to remove the CPU's
call_rcu_data structure and dispose it.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoprotect writing to per_cpu_call_rcu_data[*]
Lai Jiangshan [Thu, 15 Sep 2011 15:20:29 +0000 (11:20 -0400)] 
protect writing to per_cpu_call_rcu_data[*]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agowake up default call_rcu thread after we move the leftover callbacks
Lai Jiangshan [Thu, 15 Sep 2011 15:19:12 +0000 (11:19 -0400)] 
wake up default call_rcu thread after we move the leftover callbacks

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoavoid memory leak in call_rcu_data_free()
Lai Jiangshan [Thu, 15 Sep 2011 15:17:41 +0000 (11:17 -0400)] 
avoid memory leak in call_rcu_data_free()

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu call_rcu: fix use after free()
Lai Jiangshan [Thu, 15 Sep 2011 15:14:43 +0000 (11:14 -0400)] 
urcu call_rcu: fix use after free()

call_rcu_after_fork_child() needs to use cds_list_for_each_entry_safe to
safely iterate on the list as its item is being freed.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agouse get_cpu_call_rcu_data() for get_call_rcu_data()
Lai Jiangshan [Thu, 15 Sep 2011 15:10:31 +0000 (11:10 -0400)] 
use get_cpu_call_rcu_data() for get_call_rcu_data()

[ Impact: refactor duplicated code ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoinit maxcpus before use
Lai Jiangshan [Thu, 15 Sep 2011 15:01:38 +0000 (11:01 -0400)] 
init maxcpus before use

[ Edit:
  Covers the per-cpu call_rcu data setup (not all_cpus helper, which is
  why we did not trigger it in our tests. ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocall_rcu implementation: add missing static
Lai Jiangshan [Thu, 15 Sep 2011 14:56:56 +0000 (10:56 -0400)] 
call_rcu implementation: add missing static

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoDocument QSBR interaction with mutexes
Mathieu Desnoyers [Thu, 15 Sep 2011 14:04:30 +0000 (10:04 -0400)] 
Document QSBR interaction with mutexes

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-pointer: implement URCU_FORCE_CAST for C++ compatibility of urcu-pointer.h
Mathieu Desnoyers [Tue, 13 Sep 2011 21:00:08 +0000 (17:00 -0400)] 
urcu-pointer: implement URCU_FORCE_CAST for C++ compatibility of urcu-pointer.h

We need to be careful with those, so we do not break aliasing. Our
use-case is to cast back and forth between the same type and a void *
(or void **) type when we pass pointers to C functions. As we cast back
to the same type when the pointer is returned from the function,
aliasing should still work.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-qsbr: use rcu_thread_offline/rcu_thread_online instead of inlining them
Paolo Bonzini [Tue, 13 Sep 2011 17:49:28 +0000 (13:49 -0400)] 
urcu-qsbr: use rcu_thread_offline/rcu_thread_online instead of inlining them

* Mathieu Desnoyers wrote:

> Just to let you know that I pushed two updates into urcu: one fixes a
> grace period hang caused by a missing wakeup in the synchronize_rcu
> QSBR code. This appears to hit us due to the more fine-grained wakeup
> code brought by Paolo. The wakeup was really missing from the
> synchronize_rcu code (so Paolo's code just triggered an existing
> problem). I thought it would be good to let you know the effect: grace
> periods are delayed forever. This problem never appeared in a release
> (I caught it before).

Good catch.  Why not use rcu_thread_offline/online in synchronize_rcu,
instead of touching rcu_reader.ctr directly?  I had this in my QEMU
branch but hadn't posted yet because it was meant as a cleanup only.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoPair all_cpu call_rcu create with free
Mathieu Desnoyers [Sun, 11 Sep 2011 06:45:59 +0000 (23:45 -0700)] 
Pair all_cpu call_rcu create with free

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocall_rcu: register work threads as rcu readers
Mathieu Desnoyers [Sun, 11 Sep 2011 05:02:58 +0000 (22:02 -0700)] 
call_rcu: register work threads as rcu readers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoQSBR: add missing wakeups in synchronize_rcu code
Mathieu Desnoyers [Sun, 11 Sep 2011 06:03:09 +0000 (23:03 -0700)] 
QSBR: add missing wakeups in synchronize_rcu code

synchronize_rcu go into offline mode during grace period. It duplicates
the rcu_thread_online/offline code, and therefore adding the required
wake_up_gp() is required there too.

Failure to do so leads to grace period hangs.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocmm: do not generate code for smp_rmb/smp_wmb on x86_64
Paolo Bonzini [Sat, 10 Sep 2011 19:29:56 +0000 (12:29 -0700)] 
cmm: do not generate code for smp_rmb/smp_wmb on x86_64

We can assume, on x86, that no accesses to write-combining memory occur,
and also that there are no non-temporal load/stores (people would
presumably write those with assembly or intrinsics and put appropriate
lfence/sfence manually). In this case rmb and wmb are no-ops on x86.
according to the updated x86 memory models:

INTEL CORPORATION. Intel 64 Architecture Memory Ordering White Paper,
2007.
http://developer.intel.com/products/processor/manuals/318147.pdf

ADVANCED MICRO DEVICES. AMD x86-64 Architecture Programmer’s Manual
Volume 2: System Programming, 2007.

Paul E. McKenney. Memory Ordering in Modern Microprocessors
www.rdrop.com/users/paulmck/scalability/paper/ordering.2007.09.19a.pdf

x86 does not reorder loads vs loads, and stores vs stores when using
normal memory accesses, with the notable exceptions of Pentium Pro
(reorders reads) and WinChip (reorders writes). Therefore, it is safe
not to emit fence instructions for x86_64 cmm_smp_rmb()/cmm_smp_wmb(),
but we leave the memory fences in place for x86_32 for those two
special-cases.

Define cmm_smp_rmb and cmm_smp_wmb to be the "common" operations that
do not require fence instruction, while leaving cmm_rmb and cmm_wmb in
place for more sophisticated uses.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agocmm: let per-arch files provide cmm_smp_* barriers
Paolo Bonzini [Sat, 10 Sep 2011 19:26:19 +0000 (12:26 -0700)] 
cmm: let per-arch files provide cmm_smp_* barriers

x86 instructions lfence and sfence are rarely needed, thus we want
the cmm_smp_rmb/cmm_smp_wmb macros to be simple compiler barriers.
So, let the per-arch files override the default definitions in
arch/generic.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoOptimize caa_get_cycles() for PowerPC64
Tulio Magno Quites Machado Filho [Fri, 9 Sep 2011 05:37:11 +0000 (22:37 -0700)] 
Optimize caa_get_cycles() for PowerPC64

Make caa_get_cycles() read from the Time Base register with only 1
instruction.

[ Edit by Mathieu Desnoyers: coding style update ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
13 years agolfq/lfs tests: use call_rcu
Mathieu Desnoyers [Mon, 5 Sep 2011 01:25:21 +0000 (21:25 -0400)] 
lfq/lfs tests: use call_rcu

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoRevert "Add cds_list_empty"
Mathieu Desnoyers [Mon, 5 Sep 2011 00:11:01 +0000 (20:11 -0400)] 
Revert "Add cds_list_empty"

This reverts commit 4b7cab77f3c1c03f021cb0f7e8d150eed3f948e9.

(did duplicate cds_list_empty)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoAdd cds_list_empty
Mathieu Desnoyers [Mon, 5 Sep 2011 00:07:41 +0000 (20:07 -0400)] 
Add cds_list_empty

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agolist: Add cds_list_first_entry
Mathieu Desnoyers [Sun, 4 Sep 2011 23:48:20 +0000 (19:48 -0400)] 
list: Add cds_list_first_entry

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agorculfstack/queue: define _LGPL_SOURCE around static header include
Mathieu Desnoyers [Sat, 3 Sep 2011 14:07:41 +0000 (10:07 -0400)] 
rculfstack/queue: define _LGPL_SOURCE around static header include

... so the urcu-pointer header takes the LGPL version of rcu_dereference
and friends.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoRevert "Create per RCU flavor CDS libraries"
Mathieu Desnoyers [Sat, 3 Sep 2011 13:49:07 +0000 (09:49 -0400)] 
Revert "Create per RCU flavor CDS libraries"

This reverts commit d4b99c015229978810319cfd42e1c9763772fad8.

Minor change (not visible to end-users): this commit introduces a
liburcu-common.so to hold wfqueue, wfstack and futex fall-back code.
This .so is used by all URCU flavors, as well as liburcu-cds.so.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoRevert "CDS API: removal of rcu_read lock/unlock dep, removal of call_rcu argument...
Mathieu Desnoyers [Sat, 3 Sep 2011 13:15:14 +0000 (09:15 -0400)] 
Revert "CDS API: removal of rcu_read lock/unlock dep, removal of call_rcu argument from init"

This reverts commit 7618919ae496bda84a2efa4f2ad0abe569892a9e.

Rationale:

I thought about it some more, and had discussions with various people,
and there are a few reasons to go for a scheme where rcu read lock
should be taken by the caller, and to pass call_rcu as a parameter to
the data structure init function:

A) The advantage, as Paul E. McKenney pointed out, is that one single .so
   is enough to support all RCU flavors. Very convenient for external data
   structure containers.

B) It clearly documents where rcu read-side locks are needed, so the user
   keep control and in-depth understanding of their read-side locks.

C) When multiple API functions that require RCU read-side lock to be
   held (sometimes even the same lock) throughout a sequence of API
   calls, we have no choice but to let the caller hold the read-side
   lock.

D) Due to support of multiple nesting of rcu read-side lock, any
   "improvement" we could get by releasing the read-side lock in
   retry loops would vanish in the cases where we are called within
   nested C.S..

E) If a library uses synchronize_rcu, this should be clearly documented,
   and even frowned upon, because this involves important limitations on
   the design of the caller, and important performance hit. There are
   usually ways to reach the same result through use of call_rcu, which
   should really be used thoroughout these libraries.

F) It clearly documents when a data structure needs to use call_rcu
   internally.

G) Some very early benchmark results show that there is indeed not
   much performance gain to achieve by inlining call_rcu, even if it is
   a version with a cache for the "call_rcu structure" lookup
   (per-cpu/per-thread/global). So passing it as a parameter to
   the data structure init function should be fine, even in cases
   where it is called very often.

H) For use-cases where applications would like to use more than one
   RCU flavor concurrently (which is now supported), leaving management
   of RCU read-side C.S. to the reader allows the application to take
   more than one RCU read-side lock across API calls. It also lets the
   application specify its own call_rcu function that could handle more
   than one RCU flavor.

So for all these reasons, I reverting back to the API we have in our
last release (0.6.4).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoAdd __rcu annotation (unimplemented)
Mathieu Desnoyers [Sat, 3 Sep 2011 12:37:22 +0000 (08:37 -0400)] 
Add __rcu annotation (unimplemented)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoFix incorrect fsf address in header files
Mathieu Desnoyers [Thu, 1 Sep 2011 20:11:14 +0000 (16:11 -0400)] 
Fix incorrect fsf address in header files

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agowfstack: push returns prior stack emptiness state
Mathieu Desnoyers [Thu, 1 Sep 2011 13:31:55 +0000 (09:31 -0400)] 
wfstack: push returns prior stack emptiness state

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoMake lf stack push return if the stack was empty
Mathieu Desnoyers [Thu, 1 Sep 2011 13:28:30 +0000 (09:28 -0400)] 
Make lf stack push return if the stack was empty

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoDocument caa_container_of
Mathieu Desnoyers [Tue, 23 Aug 2011 21:22:00 +0000 (17:22 -0400)] 
Document caa_container_of

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-bp: do not call munmap for NULL registry at exit
Mathieu Desnoyers [Sat, 20 Aug 2011 17:50:08 +0000 (13:50 -0400)] 
urcu-bp: do not call munmap for NULL registry at exit

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu libraries can directly use the _LGPL_SOURCE wfqueue
Mathieu Desnoyers [Thu, 18 Aug 2011 17:41:11 +0000 (13:41 -0400)] 
urcu libraries can directly use the _LGPL_SOURCE wfqueue

No need to link dynamically with the data structure object.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agorculfstack: document "push"
Mathieu Desnoyers [Thu, 18 Aug 2011 16:13:44 +0000 (12:13 -0400)] 
rculfstack: document "push"

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoAdd runall.sh to tarball
Mathieu Desnoyers [Wed, 17 Aug 2011 21:58:30 +0000 (17:58 -0400)] 
Add runall.sh to tarball

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoFix build order of liburcu-cds-common
Mathieu Desnoyers [Wed, 17 Aug 2011 21:57:19 +0000 (17:57 -0400)] 
Fix build order of liburcu-cds-common

Caused make install to fail.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoCDS API: removal of rcu_read lock/unlock dep, removal of call_rcu argument from init
Mathieu Desnoyers [Wed, 17 Aug 2011 21:54:33 +0000 (17:54 -0400)] 
CDS API: removal of rcu_read lock/unlock dep, removal of call_rcu argument from init

* API change * for all liburcu-cds* flavors.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoFix missing check for SYS_membarrier in map header
Mathieu Desnoyers [Wed, 17 Aug 2011 21:54:07 +0000 (17:54 -0400)] 
Fix missing check for SYS_membarrier in map header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoCreate per RCU flavor CDS libraries
Mathieu Desnoyers [Wed, 17 Aug 2011 20:42:20 +0000 (16:42 -0400)] 
Create per RCU flavor CDS libraries

Introduce per-flavor concurrent data structure libraries for data
structures depending on RCU:

liburcu-cds: memb flavor (default), matches -lurcu
liburcu-cds-qsbr: qsbr flavor, matches -lurcu-qsbr
liburcu-cds-mb: mb flavor, matches -lurcu-mb
liburcu-cds-signal, matches -lurcu-signal
liburcu-cds-bp, matches -lurcu-bp

liburcu-cds-common: Data structures not depending on RCU for
synchronization.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoMerge branch 'master' into lfqueue-dev lfqueue-dev
Mathieu Desnoyers [Wed, 17 Aug 2011 10:07:35 +0000 (06:07 -0400)] 
Merge branch 'master' into lfqueue-dev

13 years agourcu-qsbr: avoid useless futex wakeups and burning CPU for long grace periods
Paolo Bonzini [Wed, 17 Aug 2011 09:42:51 +0000 (05:42 -0400)] 
urcu-qsbr: avoid useless futex wakeups and burning CPU for long grace periods

I noticed that urcu makes exactly _one_ attempt at using futexes
to avoid busy looping on synchronize_rcu.  The attached patch instead
switches from busy waiting to futexes after RCU_QS_ACTIVE_ATTEMPTS.
To limit the amount of system calls, reading threads remember whether
they already had a quiescent state in this grace period; if so they were
already removed from the list, and can avoid signaling the futex.

Performance measured with rcutorture (nreaders: 10, nupdaters: 1,
duration: 10, median of nine runs):

     RCU_QS_ACTIVE_ATTEMPTS == 100, no patch         n_updates = 292
     RCU_QS_ACTIVE_ATTEMPTS == 1, no patch           n_updates = 290
     RCU_QS_ACTIVE_ATTEMPTS == 100, with patch       n_updates = 408
     RCU_QS_ACTIVE_ATTEMPTS == 1, with patch         n_updates = 404

(the first two cases are obviously the same; the only change is
when the futex is used, but over many calls there is no difference).

This patch matches the update to the Promela model.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoapi: reimplement BUILD_BUG_ON in compiler.h
Paolo Bonzini [Wed, 17 Aug 2011 09:33:58 +0000 (05:33 -0400)] 
api: reimplement BUILD_BUG_ON in compiler.h

Even though it's just two lines of code, I'm reimplementing it
cleanly out of paranoia.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agotest api cleanup: remove unused primitives
Paolo Bonzini [Wed, 17 Aug 2011 09:31:21 +0000 (05:31 -0400)] 
test api cleanup: remove unused primitives

[ Mathieu: the rationale for this is that we can always add back that
  code if every needed. Removing leftover GPLv2 test code is an
  incentive to create the appropriate library-wide LGPL/MIT-style
  abstractions.]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoMerge branch 'master' into lfqueue-dev
Mathieu Desnoyers [Wed, 17 Aug 2011 09:28:33 +0000 (05:28 -0400)] 
Merge branch 'master' into lfqueue-dev

13 years agoput thread offline while waiting for the init flag
Paolo Bonzini [Tue, 9 Aug 2011 20:49:27 +0000 (16:49 -0400)] 
put thread offline while waiting for the init flag

Otherwise, the call_rcu thread might end up in a synchronize_rcu that
never ends.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:44:20 +0000 (16:44 -0400)] 
urcu: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS
and KICK_READER_LOOPS.  Move the definition to urcu.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-bp: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:43:21 +0000 (16:43 -0400)] 
urcu-bp: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS.
Move the definition to urcu-bp.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-qsbr: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:42:53 +0000 (16:42 -0400)] 
urcu-qsbr: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS.
Move the definition to urcu-qsbr.c.  Also remove KICK_READER_LOOPS.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agorcutorture: fix rcutorture-qsbr
Paolo Bonzini [Tue, 9 Aug 2011 20:40:29 +0000 (16:40 -0400)] 
rcutorture: fix rcutorture-qsbr

rcutorture-qsbr is not marking quiescent states, so it will always
have just one update in the whole test.  Fix it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agowfqueue: fix type-incorrect assignment
Paolo Bonzini [Tue, 9 Aug 2011 12:37:14 +0000 (08:37 -0400)] 
wfqueue: fix type-incorrect assignment

The "old_tail = q->tail, q->tail = node" assignment in wfqueue
is not type safe; q->tail is a pointer to pointer to node and the
correct value to assign is &node->next.  While the arithmetic is
the same, it is better to be tidy.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoFix tests Makefile EXTRA_DIST to use api.h
Mathieu Desnoyers [Tue, 16 Aug 2011 11:11:16 +0000 (07:11 -0400)] 
Fix tests Makefile EXTRA_DIST to use api.h

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoFix choice of default flavour in urcu/map/urcu.h
Duncan Sands [Tue, 16 Aug 2011 11:10:01 +0000 (07:10 -0400)] 
Fix choice of default flavour in urcu/map/urcu.h

Hi, I noticed in the 0.64 release (and git too) that if a flavour is not
specified explicitly then RCU_MB is chosen in urcu/map/urcu.h, while the
docs say and the Makefile expects RCU_MEMBARRIER.  Note that the header
file urcu/static/urcu.h has similar logic but uses RCU_MEMBARRIER for
the default.

Before this patch:

$ nm *.a | grep rcu_init
00000000000003c0 T rcu_init_mb
00000000000003c0 T rcu_init_mb
0000000000000000 T rcu_init_sig

After this patch:

$ nm *.a | grep rcu_init
00000000000003c0 T rcu_init_memb
00000000000003c0 T rcu_init_mb
0000000000000000 T rcu_init_sig

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoapi: remove list/hlist
Paolo Bonzini [Tue, 16 Aug 2011 10:52:54 +0000 (06:52 -0400)] 
api: remove list/hlist

Remove the parts that actually caused compilation to fail.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoapi: remove arch-specific files
Paolo Bonzini [Tue, 16 Aug 2011 10:51:55 +0000 (06:51 -0400)] 
api: remove arch-specific files

No change since they were a subset of api_gcc.h.  api_gcc.h is
renamed to api.h, and configure need not create a symlink anymore.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoapi: make api_gcc.h a superset of the other headers
Paolo Bonzini [Tue, 16 Aug 2011 10:41:06 +0000 (06:41 -0400)] 
api: make api_gcc.h a superset of the other headers

After this patch the only differences are:

- for_each_tid is now defined in api_x86.h

- HAVE_CPU_SET_T and HAVE_SCHED_SETAFFINITY are now defined in api_ppc.h

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agotests api: remove atomics
Paolo Bonzini [Fri, 12 Aug 2011 22:23:59 +0000 (18:23 -0400)] 
tests api: remove atomics

The code is #if 0'd already, remove it.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoput thread offline while waiting for the init flag
Paolo Bonzini [Tue, 9 Aug 2011 20:49:27 +0000 (16:49 -0400)] 
put thread offline while waiting for the init flag

Otherwise, the call_rcu thread might end up in a synchronize_rcu that
never ends.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:44:20 +0000 (16:44 -0400)] 
urcu: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS
and KICK_READER_LOOPS.  Move the definition to urcu.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-bp: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:43:21 +0000 (16:43 -0400)] 
urcu-bp: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS.
Move the definition to urcu-bp.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agourcu-qsbr: move private definitions to .c file
Paolo Bonzini [Tue, 9 Aug 2011 20:42:53 +0000 (16:42 -0400)] 
urcu-qsbr: move private definitions to .c file

The reader does not and should not know about RCU_QS_ACTIVE_ATTEMPTS.
Move the definition to urcu-qsbr.c.  Also remove KICK_READER_LOOPS.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agorcutorture: fix rcutorture-qsbr
Paolo Bonzini [Tue, 9 Aug 2011 20:40:29 +0000 (16:40 -0400)] 
rcutorture: fix rcutorture-qsbr

rcutorture-qsbr is not marking quiescent states, so it will always
have just one update in the whole test.  Fix it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agowfqueue: fix type-incorrect assignment
Paolo Bonzini [Tue, 9 Aug 2011 12:37:14 +0000 (08:37 -0400)] 
wfqueue: fix type-incorrect assignment

The "old_tail = q->tail, q->tail = node" assignment in wfqueue
is not type safe; q->tail is a pointer to pointer to node and the
correct value to assign is &node->next.  While the arithmetic is
the same, it is better to be tidy.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoMerge branch 'master' into lfqueue-dev
Mathieu Desnoyers [Mon, 8 Aug 2011 15:15:03 +0000 (11:15 -0400)] 
Merge branch 'master' into lfqueue-dev

13 years agoUse caa_ prefix for min() and max()
Mathieu Desnoyers [Tue, 2 Aug 2011 17:22:38 +0000 (13:22 -0400)] 
Use caa_ prefix for min() and max()

Defining min/max macros clashes with C++.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
13 years agoVersion 0.6.4, update changelog v0.6.4
Mathieu Desnoyers [Thu, 21 Jul 2011 21:25:43 +0000 (17:25 -0400)] 
Version 0.6.4, update changelog

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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