Messages in this thread |  | | Subject | Re: page pools, was Re: [PATCH v9 1/5] drm: Add a sharable drm page-pool implementation | From | Christian König <> | Date | Thu, 8 Jul 2021 09:37:41 +0200 |
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Am 08.07.21 um 06:20 schrieb Christoph Hellwig: > On Wed, Jul 07, 2021 at 12:35:23PM -0700, John Stultz wrote: >> So, as Christian mentioned, on the TTM side it's useful, as they are >> trying to avoid TLB flushes when changing caching attributes. >> >> For the dmabuf system heap purposes, the main benefit is moving the >> page zeroing to the free path, rather than the allocation path. This >> on its own doesn't save much, but allows us to defer frees (and thus >> the zeroing) to the background, which can get that work out of the hot >> path. > I really do no think that is worth it to fragment the free pages.
And I think functionality like that should be part of the common page allocator.
I mean we already have __GFP_ZERO, why not have a background kernel thread which zeros free pages when a CPU core is idle? (I'm pretty sure we already have that somehow).
Christian.
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