Hi Andrew,
This patch adds EOWNERDEAD and ENOTRECOVERABLE to all
architectures. Though there is nothing in the kernel
that uses them yet, I know of two patches in development,
one by Intel and the other by Bull, that adds robust mutex
support to pthread_mutex*.
Robust mutexes, by de-facto industry convention, return
EOWNERDEAD when the owner of a mutex dies, and returns
ENOTRECOVERABLE if the new owner decides that it is not
able to recover from the dead state, and so wants to mark
the mutex unrecoverable.
There is interest in robust mutexes in Linux, as they are
a well established tool when writing high availability
applications on non-Linux platforms.
Even though there are kernel components to the robust mutex
patches, the exact kernel ABI can be easily changed or
even completely replaced, without affecting applications,
while the patches are still in development. To achieve
this immunity, the applications need only to access robust
services through the pthreads library and they must link
only with the dynamic version of the library. This works
only because pthread robust mutexes are a de-facto
standard, enforced by standard usage by long established
applications, which any implementation of robust mutexes
is required to match if it is to be accepted.
However, one piece of the ABI that does leak through is
the value of EOWNERDEAD and ENOTRECOVERABLE. If these
values could be fixed then application writers would feel
more comfortable using these patches while they are still
in development. In addition, if the patches are never
accepted into the standard kernel, but live forever in
various high availability vendor kernels as a specialty
item, then it gives their users an unchanging ABI that they
can live with -- even when they migrate their application
binaries to a competing high availability Linux kernel.
I know that it is rare for an unused patch to be accepted;
however it has happened at least once before when there
was need -- eg, the security hooks patch, so this patch
request may not be completely out of line.
Regards,
Joe
i386 compile tested.
Signed-off-by: Joe Korty <[email protected]>
2.6.12-rc2-jak/include/asm-alpha/errno.h | 3 +++
2.6.12-rc2-jak/include/asm-generic/errno.h | 3 +++
2.6.12-rc2-jak/include/asm-mips/errno.h | 3 +++
2.6.12-rc2-jak/include/asm-parisc/errno.h | 3 +++
2.6.12-rc2-jak/include/asm-sparc/errno.h | 3 +++
2.6.12-rc2-jak/include/asm-sparc64/errno.h | 3 +++
6 files changed, 18 insertions(+)
diff -puNa include/asm-generic/errno.h~owner.notrecoverable.errnos include/asm-generic/errno.h
--- 2.6.12-rc2/include/asm-generic/errno.h~owner.notrecoverable.errnos 2005-04-12 09:54:38.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-generic/errno.h 2005-04-12 11:16:50.681480153 -0400
@@ -102,4 +102,7 @@
#define EKEYREVOKED 128 /* Key has been revoked */
#define EKEYREJECTED 129 /* Key was rejected by service */
+#define EOWNERDEAD 130 /* Owner died */
+#define ENOTRECOVERABLE 131 /* State not recoverable */
+
#endif
diff -puNa include/asm-alpha/errno.h~owner.notrecoverable.errnos include/asm-alpha/errno.h
--- 2.6.12-rc2/include/asm-alpha/errno.h~owner.notrecoverable.errnos 2005-04-12 10:04:36.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-alpha/errno.h 2005-04-12 11:16:17.548396780 -0400
@@ -116,4 +116,7 @@
#define EKEYREVOKED 134 /* Key has been revoked */
#define EKEYREJECTED 135 /* Key was rejected by service */
+#define EOWNERDEAD 136 /* Owner died */
+#define ENOTRECOVERABLE 137 /* State not recoverable */
+
#endif
diff -puNa include/asm-mips/errno.h~owner.notrecoverable.errnos include/asm-mips/errno.h
--- 2.6.12-rc2/include/asm-mips/errno.h~owner.notrecoverable.errnos 2005-04-12 10:04:36.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-mips/errno.h 2005-04-12 11:16:29.262658422 -0400
@@ -115,6 +115,9 @@
#define EKEYREVOKED 163 /* Key has been revoked */
#define EKEYREJECTED 164 /* Key was rejected by service */
+#define EOWNERDEAD 165 /* Owner died */
+#define ENOTRECOVERABLE 166 /* State not recoverable */
+
#define EDQUOT 1133 /* Quota exceeded */
#ifdef __KERNEL__
diff -puNa include/asm-parisc/errno.h~owner.notrecoverable.errnos include/asm-parisc/errno.h
--- 2.6.12-rc2/include/asm-parisc/errno.h~owner.notrecoverable.errnos 2005-04-12 10:04:36.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-parisc/errno.h 2005-04-12 11:14:19.353941346 -0400
@@ -115,5 +115,8 @@
#define ENOTSUP 252 /* Function not implemented (POSIX.4 / HPUX) */
#define ECANCELLED 253 /* aio request was canceled before complete (POSIX.4 / HPUX) */
+#define EOWNERDEAD 254 /* Owner died */
+#define ENOTRECOVERABLE 255 /* State not recoverable */
+
#endif
diff -puNa include/asm-sparc/errno.h~owner.notrecoverable.errnos include/asm-sparc/errno.h
--- 2.6.12-rc2/include/asm-sparc/errno.h~owner.notrecoverable.errnos 2005-04-12 10:04:36.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-sparc/errno.h 2005-04-12 11:15:55.987596555 -0400
@@ -107,4 +107,7 @@
#define EKEYREVOKED 130 /* Key has been revoked */
#define EKEYREJECTED 131 /* Key was rejected by service */
+#define EOWNERDEAD 132 /* Owner died */
+#define ENOTRECOVERABLE 133 /* State not recoverable */
+
#endif
diff -puNa include/asm-sparc64/errno.h~owner.notrecoverable.errnos include/asm-sparc64/errno.h
--- 2.6.12-rc2/include/asm-sparc64/errno.h~owner.notrecoverable.errnos 2005-04-12 10:04:36.000000000 -0400
+++ 2.6.12-rc2-jak/include/asm-sparc64/errno.h 2005-04-12 11:16:01.526774474 -0400
@@ -107,4 +107,7 @@
#define EKEYREVOKED 130 /* Key has been revoked */
#define EKEYREJECTED 131 /* Key was rejected by service */
+#define EOWNERDEAD 132 /* Owner died */
+#define ENOTRECOVERABLE 133 /* State not recoverable */
+
#endif /* !(_SPARC64_ERRNO_H) */
_
-
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