Messages in this thread | | | Date | Sat, 14 Feb 2015 16:40:36 +0900 | From | Gioh Kim <> | Subject | Re: [PATCH 0/4] mm: cma: add some debug information for CMA |
| |
2015-02-13 오후 12:03에 Joonsoo Kim 이(가) 쓴 글: > On Fri, Feb 13, 2015 at 01:15:40AM +0300, Stefan Strogin wrote: >> Hi all. >> >> Sorry for the long delay. Here is the second attempt to add some facility >> for debugging CMA (the first one was "mm: cma: add /proc/cmainfo" [1]). >> >> This patch set is based on v3.19 and Sasha Levin's patch set >> "mm: cma: debugfs access to CMA" [2]. >> It is also available on git: >> git://github.com/stefanstrogin/cmainfo -b cmainfo-v2 >> >> We want an interface to see a list of currently allocated CMA buffers and >> some useful information about them (like /proc/vmallocinfo but for physically >> contiguous buffers allocated with CMA). >> >> Here is an example use case when we need it. We want a big (megabytes) >> CMA buffer to be allocated in runtime in default CMA region. If someone >> already uses CMA then the big allocation can fail. If it happens then with >> such an interface we could find who used CMA at the moment of failure, who >> caused fragmentation (possibly ftrace also would be helpful here) and so on. > > Hello, > > So, I'm not sure that information about allocated CMA buffer is really > needed to solve your problem. You just want to know who uses default CMA > region and you can know it by adding tracepoint in your 4/4 patch. We > really need this custom allocation tracer? What can we do more with > this custom tracer to solve your problem? Could you more specific > about your problem and how to solve it by using this custom tracer? > >> >> These patches add some files to debugfs when CONFIG_CMA_DEBUGFS is enabled. > > If this tracer is justifiable, I think that making it conditional is > better than just enabling always on CONFIG_CMA_DEBUGFS. Some users > don't want to this feature although they enable CONFIG_CMA_DEBUGFS. > > Thanks. >
Hello,
Thanks for your work. It must be helpful to me.
What about add another option to activate stack-trace? In my platform I know all devices using cma area, so I usually don't need stack-trace.
| |