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@xxxxxxxxxx > > 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@xxxxxxxxx> Reinette -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
