Diffstat (limited to 'Documentation')
2 files changed, 28 insertions, 2 deletions
diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 3e4b3dd1e04..83577f0232a 100644
@@ -33,6 +33,9 @@ When mounting an XFS filesystem, the following options are accepted.
removing extended attributes) the on-disk superblock feature
bit field will be updated to reflect this format being in use.
+ CRC enabled filesystems always use the attr2 format, and so
+ will reject the noattr2 mount option if it is set.
Enables the use of block layer write barriers for writes into
the journal and unwritten extent conversion. This allows for
diff --git a/Documentation/powerpc/transactional_memory.txt b/Documentation/powerpc/transactional_memory.txt
index c907be41d60..dc23e58ae26 100644
@@ -147,6 +147,25 @@ Example signal handler:
+When in an active transaction that takes a signal, we need to be careful with
+the stack. It's possible that the stack has moved back up after the tbegin.
+The obvious case here is when the tbegin is called inside a function that
+returns before a tend. In this case, the stack is part of the checkpointed
+transactional memory state. If we write over this non transactionally or in
+suspend, we are in trouble because if we get a tm abort, the program counter and
+stack pointer will be back at the tbegin but our in memory stack won't be valid
+To avoid this, when taking a signal in an active transaction, we need to use
+the stack pointer from the checkpointed state, rather than the speculated
+state. This ensures that the signal context (written tm suspended) will be
+written below the stack required for the rollback. The transaction is aborted
+becuase of the treclaim, so any memory written between the tbegin and the
+signal will be rolled back anyway.
+For signals taken in non-TM or suspended mode, we use the
+normal/non-checkpointed stack pointer.
Failure cause codes used by kernel
@@ -155,14 +174,18 @@ These are defined in <asm/reg.h>, and distinguish different reasons why the
kernel aborted a transaction:
TM_CAUSE_RESCHED Thread was rescheduled.
+ TM_CAUSE_TLBI Software TLB invalide.
TM_CAUSE_FAC_UNAV FP/VEC/VSX unavailable trap.
TM_CAUSE_SYSCALL Currently unused; future syscalls that must abort
transactions for consistency will use this.
TM_CAUSE_SIGNAL Signal delivered.
TM_CAUSE_MISC Currently unused.
+ TM_CAUSE_ALIGNMENT Alignment fault.
+ TM_CAUSE_EMULATE Emulation that touched memory.
-These can be checked by the user program's abort handler as TEXASR[0:7].
+These can be checked by the user program's abort handler as TEXASR[0:7]. If
+bit 7 is set, it indicates that the error is consider persistent. For example
+a TM_CAUSE_ALIGNMENT will be persistent while a TM_CAUSE_RESCHED will not.q