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9 commits

Author SHA1 Message Date
Alex Bennée a74c82c8dc tests/rcutorture: mild documenting refactor of update thread
This is mainly to help with reasoning what the test is trying to do.
We can move rcu_stress_idx to a local variable as there is only ever
one updater thread. I've also added an assert to catch the case where
we end up updating the current structure to itself which is the only
way I can see the mberror cases we are seeing on Travis.

We shall see if the rcutorture test failures go away now.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Message-Id: <20200225124710.14152-5-alex.bennee@linaro.org>
2020-02-25 17:42:59 +00:00
Alex Bennée ea70ccff65 tests/rcutorture: better document locking of stats
This is pure code motion with no functional effect.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200225124710.14152-4-alex.bennee@linaro.org>
2020-02-25 17:42:59 +00:00
Alex Bennée 804c96848b tests/rcutorture: update usage hint
Although documented in the comments we don't display all the various
invocations we can in the usage.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200225124710.14152-3-alex.bennee@linaro.org>
2020-02-25 17:42:59 +00:00
Paolo Bonzini b9b7581754 rcutorture: remove synchronize_rcu from readers
This gives much worse numbers for readers, especially if synchronize_rcu
is made more expensive as is the case with --enable-membarrier.  Before:

   $ tests/rcutorture 10 stress 10
   n_reads: 98304  n_updates: 529  n_mberror: 0
   rcu_stress_count: 98302 2 0 0 0 0 0 0 0 0 0

After:

   $ tests/rcutorture 10 stress 10
   n_reads: 165158482  n_updates: 429  n_mberror: 0
   rcu_stress_count: 165154364 4118 0 0 0 0 0 0 0 0 0

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-12 16:12:47 +01:00
Peter Maydell 79ffb277ec tests: Remove unnecessary glib.h includes
Remove glib.h includes, as it is provided by osdep.h.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-06-07 18:19:24 +03:00
Peter Maydell 681c28a33e tests: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
2016-02-16 14:29:27 +00:00
Paolo Bonzini 8a5956ad63 rcu tests: fix compilation on 32-bit ppc
32-bit PPC cannot do atomic operations on long long.  Inside the loops,
we are already using local counters that are summed at the end of
the run---with some exceptions (rcu_stress_count for rcutorture,
n_nodes for test-rcu-list): fix them to use the same technique.
For test-rcu-list, remove the mostly unused member "val" from the
list.  Then, use a mutex to protect the global counts.

Performance does not matter there because every thread will only enter
the critical section once.

Remaining uses of atomic instructions are for ints or pointers.

Reported-by: Andreas Faerber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-25 13:37:10 +01:00
Paolo Bonzini d62cb4f2fd rcu: allow nesting of rcu_read_lock/rcu_read_unlock
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-02 16:55:10 +01:00
Paolo Bonzini 8fda74a52b rcu: add rcutorture
rcutorture is the unit test for rcu.

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-02 16:55:10 +01:00