[IA64] another perfmon fix (take2)
- pfm_context_load(): change return value from EINVAL to EBUSY
when context is already loaded.
- pfm_check_task_state(): pass test if context state is MASKED.
It is safe to give access on PFM_CTX_MASKED because the PMU
state (PMD) is stable and saved in software state.
This helps multiplexing programs such as the example given
in libpfm-3.1.
Signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index fd4f3be..71c1016 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -4215,7 +4215,7 @@
DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
req->load_pid,
ctx->ctx_state));
- return -EINVAL;
+ return -EBUSY;
}
DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
@@ -4717,16 +4717,26 @@
if (task == current || ctx->ctx_fl_system) return 0;
/*
- * if context is UNLOADED we are safe to go
+ * we are monitoring another thread
*/
- if (state == PFM_CTX_UNLOADED) return 0;
-
- /*
- * no command can operate on a zombie context
- */
- if (state == PFM_CTX_ZOMBIE) {
- DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
- return -EINVAL;
+ switch(state) {
+ case PFM_CTX_UNLOADED:
+ /*
+ * if context is UNLOADED we are safe to go
+ */
+ return 0;
+ case PFM_CTX_ZOMBIE:
+ /*
+ * no command can operate on a zombie context
+ */
+ DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
+ return -EINVAL;
+ case PFM_CTX_MASKED:
+ /*
+ * PMU state has been saved to software even though
+ * the thread may still be running.
+ */
+ if (cmd != PFM_UNLOAD_CONTEXT) return 0;
}
/*