On 2022/12/18 9:20, Masami Hiramatsu (Google) wrote:
> On Thu, 8 Dec 2022 22:21:30 +0800
> Wenchao Hao <haowenchao@xxxxxxxxxx> wrote:
>
>> The result of allocation is not printed in trace_cma_alloc_finish
>> now, while it's important to do it so we can set filters to catch
>> specific error on allocation or trigger some operations on specific
>> error.
>>
>> Although we have printed the result in log, but the log is
>> conditional and could not be filtered by tracing event.
>>
>> What's more, it introduce little overhead to print this result.
>> The result of allocation is named as errorno in trace.
>
> This looks good to me. BTW, with this change, cma_alloc_class has only
> one event - cma_alloc_busy_retry. If so, can we remove the cma_alloc_class?
>
> Thank you,
>
Sorry, I got COVID-19 and just recovered, so did not response your email in time.
The cma_alloc_class should be removed. Since Andrew has applied this patch,
I would send another one to remove it.
>>
>> Signed-off-by: Wenchao Hao <haowenchao@xxxxxxxxxx>
>> ---
>> include/trace/events/cma.h | 32 +++++++++++++++++++++++++++++---
>> mm/cma.c | 2 +-
>> 2 files changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
>> index 3d708dae1542..ef75ea606ab2 100644
>> --- a/include/trace/events/cma.h
>> +++ b/include/trace/events/cma.h
>> @@ -91,12 +91,38 @@ TRACE_EVENT(cma_alloc_start,
>> __entry->align)
>> );
>>
>> -DEFINE_EVENT(cma_alloc_class, cma_alloc_finish,
>> +TRACE_EVENT(cma_alloc_finish,
>>
>> TP_PROTO(const char *name, unsigned long pfn, const struct page *page,
>> - unsigned long count, unsigned int align),
>> + unsigned long count, unsigned int align, int errorno),
>>
>> - TP_ARGS(name, pfn, page, count, align)
>> + TP_ARGS(name, pfn, page, count, align, errorno),
>> +
>> + TP_STRUCT__entry(
>> + __string(name, name)
>> + __field(unsigned long, pfn)
>> + __field(const struct page *, page)
>> + __field(unsigned long, count)
>> + __field(unsigned int, align)
>> + __field(int, errorno)
>> + ),
>> +
>> + TP_fast_assign(
>> + __assign_str(name, name);
>> + __entry->pfn = pfn;
>> + __entry->page = page;
>> + __entry->count = count;
>> + __entry->align = align;
>> + __entry->errorno = errorno;
>> + ),
>> +
>> + TP_printk("name=%s pfn=0x%lx page=%p count=%lu align=%u errorno=%d",
>> + __get_str(name),
>> + __entry->pfn,
>> + __entry->page,
>> + __entry->count,
>> + __entry->align,
>> + __entry->errorno)
>> );
>>
>> DEFINE_EVENT(cma_alloc_class, cma_alloc_busy_retry,
>> diff --git a/mm/cma.c b/mm/cma.c
>> index 4a978e09547a..a75b17b03b66 100644
>> --- a/mm/cma.c
>> +++ b/mm/cma.c
>> @@ -491,7 +491,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
>> start = bitmap_no + mask + 1;
>> }
>>
>> - trace_cma_alloc_finish(cma->name, pfn, page, count, align);
>> + trace_cma_alloc_finish(cma->name, pfn, page, count, align, ret);
>>
>> /*
>> * CMA can allocate multiple page blocks, which results in different
>> --
>> 2.32.0
>>
>
>
