#
fda81588 |
|
05-Apr-2023 |
Benjamin Gray <bgray@linux.ibm.com> |
selftests/powerpc/dscr: Add lockstep test cases to DSCR explicit tests Add new cases to the relevant tests that use explicitly synchronized threads to test the behaviour across context switches with less randomness. By locking the participants to the same CPU we guarantee a context switch occurs each time they make progress, which is a likely failure point if the kernel is not tracking the thread local DSCR correctly. The random case is left in to keep exercising potential edge cases. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230406043320.125138-5-bgray@linux.ibm.com
|
#
564cbc87 |
|
23-Oct-2017 |
Mark Rutland <mark.rutland@arm.com> |
locking/atomics, selftests/powerpc: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. The bulk of the kernel code can be transformed via Coccinelle to use {READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(), and not the implementation itself. As such, it has the potential to break homebrew ACCESS_ONCE() macros seen in some user code in the kernel tree (e.g. the virtio code, as fixed in commit ea9156fb3b71d9f7). To avoid fragility if/when that transformation occurs, and to align with the preferred usage of {READ,WRITE}_ONCE(), this patch updates the DSCR selftest code to use READ_ONCE() rather than ACCESS_ONCE(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-11-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
#
4c6315f8 |
|
20-May-2015 |
Anshuman Khandual <khandual@linux.vnet.ibm.com> |
selftests/powerpc: Add test for system wide DSCR default This patch adds a test case for the system wide DSCR default value, which when changed through it's sysfs interface must be visible to all threads reading DSCR either through the privilege state SPR or the problem state SPR. The DSCR value change should be immediate as well. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|