[PATCH 11/11] erofs: support tracepoint

[chao@kernel.org (Chao Yu)]

Hi Xiang,

On 2018/7/3 17:44, Gao Xiang wrote:
> Hi Chao,
> 
> On 2018/6/22 10:01, Chao Yu wrote:
>> Add tracepoints for ->readpage{,s}, ->lookup.
>>
>> Signed-off-by: Chao Yu <yuchao0 at huawei.com> ---
> 
> Very useful feature (I could use it for the new unzip implementation :) )

It seems we need more tracepoints for debug or accounting, but now I just add
basic ones, let's add more. ;)

> 
>>  fs/erofs/data.c              |   8 +++
>>  fs/erofs/namei.c             |   5 ++
>>  fs/erofs/super.c             |   2 +
>>  fs/erofs/unzip.c             |  10 +++-
>>  include/trace/events/erofs.h | 109 +++++++++++++++++++++++++++++++++++
>>  5 files changed, 133 insertions(+), 1 deletion(-)
>>  create mode 100644 include/trace/events/erofs.h
>>
>> +	trace_erofs_readpage(page, true);
>> +
>>  	bio = erofs_read_raw_page(NULL, page->mapping,
>>  		page, &last_block, 1, false);
>>  
>> @@ -354,6 +359,9 @@ static int erofs_raw_access_readpages(struct file *filp,
>>  	erofs_off_t last_block;
>>  	struct bio *bio = NULL;
>>  	gfp_t gfp = readahead_gfp_mask(mapping);
>> +	struct page *page = list_last_entry(pages, struct page, lru);
>> +
>> +	trace_erofs_readpages(mapping->host, page, nr_pages, true);
>>  
>>  	for (; nr_pages; --nr_pages) {
>>  		struct page *page = list_entry(pages->prev, struct page, lru);
> 
> minor, how about remove the in-loop 'page' defination?

Okay, let me remove this.

Thanks,

> 
> Reviewed-by: Gao Xiang <gaoxiang25 at huawei.com>
> 
> Thanks,
> Gao Xiang
> 
>> diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c
>> index e30294b279d1..b701d9ba52a6 100644
>> --- a/fs/erofs/namei.c
>> +++ b/fs/erofs/namei.c