Re: [PATCH] mm: cma: add trace events for CMA allocations and freeings

From: Joonsoo Kim
Date: Thu Apr 02 2015 - 03:33:15 EST


Hello,

On Wed, Apr 01, 2015 at 04:31:43PM +0300, Stefan Strogin wrote:
> Add trace events for cma_alloc() and cma_release().
>
> The cma_alloc tracepoint is used both for successful and failed allocations,
> in case of allocation failure pfn=-1UL is stored and printed.
>
> Signed-off-by: Stefan Strogin <stefan.strogin@xxxxxxxxx>
> ---
>
> Took out from the patch set "mm: cma: add some debug information for CMA" v4
> (http://thread.gmane.org/gmane.linux.kernel.mm/129903) because of probable
> uselessness of the rest of the patches.

I think that patch 5/5 in previous submission is handy and
simple to merge. Although we can calculate it by using bitmap,
it would be good to get that information(used size and maxchunk size)
directly.


> @@ -414,6 +416,8 @@ struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align)
> start = bitmap_no + mask + 1;
> }
>
> + trace_cma_alloc(page ? pfn : -1UL, page, count);
> +

I think that tracing align is also useful.
Is there any reason not to include it?

Thanks.

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