Messages in this thread | | | Subject | Re: [RFC PATCH 0/3] Interface for higher order contiguous allocations | From | Reinette Chatre <> | Date | Thu, 15 Feb 2018 12:22:33 -0800 |
| |
Hi Mike,
On 2/12/2018 2:20 PM, Mike Kravetz wrote: > These patches came out of the "[RFC] mmap(MAP_CONTIG)" discussions at: > http://lkml.kernel.org/r/21f1ec96-2822-1189-1c95-79a2bb491571@oracle.com > > One suggestion in that thread was to create a friendlier interface that > could be used by drivers and others outside core mm code to allocate a > contiguous set of pages. The alloc_contig_range() interface is used for > this purpose today by CMA and gigantic page allocation. However, this is > not a general purpose interface. So, wrap alloc_contig_range() in the > more general interface: > > struct page *find_alloc_contig_pages(unsigned int order, gfp_t gfp, int nid, > nodemask_t *nodemask) > > No underlying changes are made to increase the likelihood that a contiguous > set of pages can be found and allocated. Therefore, any user of this > interface must deal with failure. The hope is that this interface will be > able to satisfy some use cases today.
As discussed in another thread a new feature, Cache Pseudo-Locking, requires large contiguous regions. Until now I just exposed alloc_gigantic_page() to handle these allocations in my testing. I now moved to using find_alloc_contig_pages() as introduced here and all my tests passed. I do hope that an API supporting large contiguous regions become available.
Thank you very much for creating this.
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Reinette
| |