Creation of kthreads is not RCU-specific, so this commit abstracts
out torture_create_kthread(), saving a few tens of lines of code in
the process.
This change requires modifying VERBOSE_TOROUT_ERRSTRING() to take a
non-const string, so that _torture_create_kthread() can avoid an
open-coded substitute.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit adds a missing error return to the code path that creates
the rcu_torture_barrier() kthread.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Not all of the rcutorture kthreads waited for kthread_should_stop()
before returning from their top-level functions, and none of them
used torture_shutdown_absorb() properly. These problems can result in
segfaults and hangs at shutdown time, and some recent changes perturbed
timing sufficiently to make them much more probable. This commit
therefore creates a torture_kthread_stopping() function that does the
proper kthread shutdown dance in one centralized location.
Accommodate this grouping by making VERBOSE_TOROUT_STRING() capable of
taking a non-const string as its argument, which allows the new
torture_kthread_stopping() to pass its "title" argument directly to
the updated version of VERBOSE_TOROUT_STRING().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
A few "stealth-start rcutorture kthreads" have accumulated over the years,
so this commit adds console-log announcements (but only if the torture
tests are running verbose).
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit applies some simple cleanups to rcu_torture_init() error
checking.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because auto-shutdown of torture testing is not specific to RCU,
this commit moves the auto-shutdown function to kernel/torture.c.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because stuttering the test load (stopping and restarting it) is useful
for non-RCU testing, this commit moves the load-stuttering functionality
to kernel/torture.c.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit introduces the torture_must_stop() function in order to
keep use of the fullstop variable local to kernel/torture.c. There
is also a torture_must_stop_irq() counterpart for use from RCU callbacks,
timeout handlers, and the like.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because handling the race between rmmod and system shutdown is not
specific to RCU, this commit abstracts torture_shutdown_notify(),
placing this code into kernel/torture.c. This change also allows
fullstop_mutex to be private to kernel/torture.c.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit creates a torture_cleanup() that handles the generic
cleanup actions local to kernel/torture.c.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit creates torture_init_begin() and torture_init_end() functions
to abstract locking and allow the torture_type and verbose variables
in kernel/torture.o to become static. With a bit more abstraction,
fullstop_mutex will also become static.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because online/offline torturing is not specific to RCU, this commit
abstracts it into the kernel/torture.c module to allow other torture
tests to use it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The torture_shuffle() function forces each CPU in turn to go idle
periodically in order to check for problems interacting with per-CPU
variables and with dyntick-idle mode. Because this sort of debugging
is not specific to RCU, this commit abstracts that functionality.
This in turn requires abstracting some additional infrastructure.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because handling races between rmmod and normal shutdown is not specific
to rcutorture, this commit renames rcutorture_shutdown_absorb() to
torture_shutdown_absorb() and pulls it out into then kernel/torture.c
module. This implies pulling the fullstop mechanism into kernel/torture.c
as well.
The exporting of fullstop and fullstop_mutex is ugly and must die.
And it does in fact die in later commits that introduce higher-level
APIs that encapsulate both of these variables.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>`
These diagnostic macros are not confined to torturing RCU, so this commit
makes them available to other torture tests. Also removed the do-while
from TOROUT_STRING() in response to checkpatch complaints.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Since it doesn't do printk()s anymore anyway, this commit renames these
macros from PRINTK to TOROUT (short for torture output).
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Create a torture_param() macro and apply it to rcutorture in order to
save a few lines of code. This same macro may be applied to other
torture frameworks.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because rcu_torture_random() will be used by the locking equivalent to
rcutorture, pull it out into its own module. This new module cannot
be separately configured, instead, use the Kconfig "select" statement
from the Kconfig options of tests depending on it.
Suggested-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit does a code-style cleanup so that the first curly brace
of an initializer does not appear at the beginning of a line.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull vfs updates from Al Viro:
"Assorted stuff; the biggest pile here is Christoph's ACL series. Plus
assorted cleanups and fixes all over the place...
There will be another pile later this week"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits)
__dentry_path() fixes
vfs: Remove second variable named error in __dentry_path
vfs: Is mounted should be testing mnt_ns for NULL or error.
Fix race when checking i_size on direct i/o read
hfsplus: remove can_set_xattr
nfsd: use get_acl and ->set_acl
fs: remove generic_acl
nfs: use generic posix ACL infrastructure for v3 Posix ACLs
gfs2: use generic posix ACL infrastructure
jfs: use generic posix ACL infrastructure
xfs: use generic posix ACL infrastructure
reiserfs: use generic posix ACL infrastructure
ocfs2: use generic posix ACL infrastructure
jffs2: use generic posix ACL infrastructure
hfsplus: use generic posix ACL infrastructure
f2fs: use generic posix ACL infrastructure
ext2/3/4: use generic posix ACL infrastructure
btrfs: use generic posix ACL infrastructure
fs: make posix_acl_create more useful
fs: make posix_acl_chmod more useful
...
rcu_dereference_check_fdtable() looks very wrong,
1. rcu_my_thread_group_empty() was added by 844b9a8707 "vfs: fix
RCU-lockdep false positive due to /proc" but it doesn't really
fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
hit the same race with get_files_struct().
And otoh rcu_my_thread_group_empty() can suppress the correct
warning if the caller is the CLONE_FILES (without CLONE_THREAD)
task.
2. files->count == 1 check is not really right too. Even if this
files_struct is not shared it is not safe to access it lockless
unless the caller is the owner.
Otoh, this check is sub-optimal. files->count == 0 always means
it is safe to use it lockless even if files != current->files,
but put_files_struct() has to take rcu_read_lock(). See the next
patch.
This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.
fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull RCU updates from Ingo Molnar:
- add RCU torture scripts/tooling
- static analysis improvements
- update RCU documentation
- miscellaneous fixes
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
rcu: Remove "extern" from function declarations in kernel/rcu/rcu.h
rcu: Remove "extern" from function declarations in include/linux/*rcu*.h
rcu/torture: Dynamically allocate SRCU output buffer to avoid overflow
rcu: Don't activate RCU core on NO_HZ_FULL CPUs
rcu: Warn on allegedly impossible rcu_read_unlock_special() from irq
rcu: Add an RCU_INITIALIZER for global RCU-protected pointers
rcu: Make rcu_assign_pointer's assignment volatile and type-safe
bonding: Use RCU_INIT_POINTER() for better overhead and for sparse
rcu: Add comment on evaluate-once properties of rcu_assign_pointer().
rcu: Provide better diagnostics for blocking in RCU callback functions
rcu: Improve SRCU's grace-period comments
rcu: Fix CONFIG_RCU_FANOUT_EXACT for odd fanout/leaf values
rcu: Fix coccinelle warnings
rcutorture: Stop tracking FSF's postal address
rcutorture: Move checkarg to functions.sh
rcutorture: Flag errors and warnings with color coding
rcutorture: Record results from repeated runs of the same test scenario
rcutorture: Test summary at end of run with less chattiness
rcutorture: Update comment in kvm.sh listing typical RCU trace events
rcutorture: Add tracing-enabled version of TREE08
...
Paul E. McKenney
Linus Torvalds
Oleg Nesterov
Ingo Molnar