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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-11-26 05:35:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-26 09:29:21 +0100 |
| commit | c6567f642e20bcc79abed030f44be5b0d6da2ded (patch) | |
| tree | eff0dee5075d220b46019019f8e0d8e8a7bd30f3 /kernel | |
| parent | d99be40aff88722ab03ee295e4f6c13a4cca9a3d (diff) | |
| download | lwn-c6567f642e20bcc79abed030f44be5b0d6da2ded.tar.gz lwn-c6567f642e20bcc79abed030f44be5b0d6da2ded.zip | |
hw-breakpoints: Improve in-kernel event creation error granularity
In fail case, perf_event_create_kernel_counter() returns NULL
instead of an error, which doesn't help us to inform the user
about the origin of the problem from the outer most callers.
Often we can just return -EINVAL, which doesn't help anyone when
it's eventually about a memory allocation failure.
Then, this patch makes perf_event_create_kernel_counter() always
return a detailed error code.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1259210142-5714-2-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_event.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 35df94e344f2..34a1b9d7633e 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4780,14 +4780,17 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, */ ctx = find_get_context(pid, cpu); - if (IS_ERR(ctx)) - return NULL; + if (IS_ERR(ctx)) { + err = PTR_ERR(ctx); + goto err_exit; + } event = perf_event_alloc(attr, cpu, ctx, NULL, NULL, callback, GFP_KERNEL); - err = PTR_ERR(event); - if (IS_ERR(event)) + if (IS_ERR(event)) { + err = PTR_ERR(event); goto err_put_context; + } event->filp = NULL; WARN_ON_ONCE(ctx->parent_ctx); @@ -4804,11 +4807,10 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, return event; -err_put_context: - if (err < 0) - put_ctx(ctx); - - return NULL; + err_put_context: + put_ctx(ctx); + err_exit: + return ERR_PTR(err); } EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |