From: stephane eranian Date: Mon, 18 Apr 2005 18:42:00 +0000 (-0700) Subject: [IA64] another perfmon fix (take2) X-Git-Tag: v2.6.12-rc4~117^2~5^2~4 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a5a70b75d93b26e14c0c5e759099d602a480b9e2;p=linux-2.6 [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 Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index fd4f3be6e8..71c101601e 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -4215,7 +4215,7 @@ pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs) 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 @@ recheck: if (task == current || ctx->ctx_fl_system) return 0; /* - * if context is UNLOADED we are safe to go - */ - if (state == PFM_CTX_UNLOADED) return 0; - - /* - * no command can operate on a zombie context + * we are monitoring another thread */ - 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; } /*