Re: [PATCH 1/3] CMA: Fix the bug that CMA's page number is substructed twice

From: Joonsoo Kim
Date: Mon Dec 29 2014 - 23:48:32 EST

On Thu, Dec 25, 2014 at 05:43:26PM +0800, Hui Zhu wrote:
> In Joonsoo's CMA patch "CMA: always treat free cma pages as non-free on
> watermark checking" [1], it changes __zone_watermark_ok to substruct CMA
> pages number from free_pages if system use CMA:
> if (IS_ENABLED(CONFIG_CMA) && z->managed_cma_pages)
> free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);


In fact, without that patch, watermark checking has a problem in current kernel.
If there is reserved CMA region, watermark check for high order
allocation is done loosly. See following thread.

Your patch can fix this situation, so, how about submitting this patch


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at