Hello,
On 11/21/2012 9:36 AM, Andrew Morton wrote:
On Wed, 21 Nov 2012 09:08:52 +0100 Marek Szyprowski m.szyprowski@samsung.com wrote:
Hello,
On 11/20/2012 8:33 PM, Andrew Morton wrote:
On Tue, 20 Nov 2012 15:31:45 +0100 Marek Szyprowski m.szyprowski@samsung.com wrote:
dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag, regardless the flags provided by the caller. This causes excessive pruning of emergency memory pools without any good reason. Additionaly, on ARM architecture any driver which is using dmapools will sooner or later trigger the following error: "ERROR: 256 KiB atomic DMA coherent pool is too small! Please increase it with coherent_pool= kernel parameter!". Increasing the coherent pool size usually doesn't help much and only delays such error, because all GFP_ATOMIC DMA allocations are always served from the special, very limited memory pool.
Is this problem serious enough to justify merging the patch into 3.7? And into -stable kernels?
I wonder if it is a good idea to merge such change at the end of current -rc period.
I'm not sure what you mean by this.
But what we do sometimes if we think a patch needs a bit more real-world testing before backporting is to merge it into -rc1 in the normal merge window, and tag it for -stable backporting. That way it gets a few weeks(?) testing in mainline before getting backported.
I just wondered that if it gets merged to v3.7-rc7 there won't be much time for real-world testing before final v3.7 release. This patch is in linux-next for over a week and I'm not aware of any issues, but -rc releases gets much more attention and testing than linux-next tree.
If You think it's fine to put such change to v3.7-rc7 I will send a pull request and tag it for stable asap.
Best regards