On Fri, Sep 13, 2019 at 12:09 AM Thomas Hellström (VMware) thomas_os@shipmail.org wrote:
From: Thomas Hellstrom thellstrom@vmware.com
Commit 4daa4fba3a38 ("gpu: drm: ttm: Adding new return type vm_fault_t") broke TTM prefaulting. Since vmf_insert_mixed() typically always returns VM_FAULT_NOPAGE, prefaulting stops after the second PTE.
Restore (almost) the original behaviour. Unfortunately we can no longer with the new vm_fault_t return type determine whether a prefaulting PTE insertion hit an already populated PTE, and terminate the insertion loop. Instead we continue with the pre-determined number of prefaults.
Fixes: 4daa4fba3a38 ("gpu: drm: ttm: Adding new return type vm_fault_t") Cc: Souptick Joarder jrdr.linux@gmail.com Cc: Christian König christian.koenig@amd.com Signed-off-by: Thomas Hellstrom thellstrom@vmware.com
This commit merged into 4.19. Need to Cc stable.
Cc: stable@vger.kernel.org # v4.19+
drivers/gpu/drm/ttm/ttm_bo_vm.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 5a580adeb9d1..aa18e8a53727 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -290,15 +290,13 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, else ret = vmf_insert_pfn(&cvma, address, pfn);
/** Somebody beat us to this PTE or prefaulting to* an already populated PTE, or prefaulting error.*/if (unlikely((ret == VM_FAULT_NOPAGE && i > 0)))break;else if (unlikely(ret & VM_FAULT_ERROR))goto out_io_unlock;
/* Never error on prefaulted PTEs */if (unlikely((ret & VM_FAULT_ERROR))) {if (i == 0)goto out_io_unlock;elsebreak;} address += PAGE_SIZE; if (unlikely(++page_offset >= page_last))-- 2.20.1