From: Nitin Gupta <nitin.m.gupta@xxxxxxxxxx> Date: Tue, 20 Jun 2017 18:05:53 -0700 > Patch 1/4: Core changes needed to add 16G hugepage support: To map a > single 16G hugepage, two PUD entries are used. Each PUD entry maps > 8G portion of a 16G page. This page table encoding scheme is same as > that used for hugepages at PMD level (8M, 256M and 2G pages) where > each PMD entry points successively to 8M regions within a page. No > page table entries below the PUD level are allocated for 16G > hugepage since those are not required. > > TSB entries for a 16G page are created at every 4M boundary since > the HUGE_TSB is used for these pages which is configured with page > size of 4M. When walking page tables (on a TSB miss), bits [32:22] > are transferred from vaddr to PUD to resolve addresses at 4M > boundary. The resolved address mapping is then stored in HUGE_TSB. Ok this is a new feature. > Patch 2/4: get_user_pages() etc. are used for direct IO. These > functions were not aware of hugepages at the PUD level and would try > to continue walking page tables beyond the PUD level. Since 16G > hugepages have page tables allocated till PUD level only, these > accesses would result in invalid access. This patch adds the case > for PUD huge pages to these functions. > > Patch 3/4: Fixes a bug in gup_huge_pmd() which caused wrong page > within a hugepage to be considered as the head page. gup_huge_pud() > already has this fix. These are bug fixes that appear to be relevant for mainline right? Please submit these two separately. > Patch 4/4: Patch 1 added the case of PUD entry being huge in page > table walk and alloc functions. This new case further increased > nesting in these functions and made them harder to follow. This > patch flattens these functions for better readability. Ok, this is a cleanup and can go along with the new feature patch #1. So submit the two bug fixes against 'sparc' GIT, then when I next merge 'sparc' into 'sparc-next', you can submit #1 and #4. THanks. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
