From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 006/131] drm/i915: convert get_user_pages() --> pin_user_pages() Date: Wed, 03 Jun 2020 15:56:37 -0700 Message-ID: <20200603225637.pX0j1WfEq%akpm@linux-foundation.org> References: <20200603155549.e041363450869eaae4c7f05b@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:37894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725863AbgFCW4j (ORCPT ); Wed, 3 Jun 2020 18:56:39 -0400 In-Reply-To: <20200603155549.e041363450869eaae4c7f05b@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: airlied@linux.ie, akpm@linux-foundation.org, chris@chris-wilson.co.uk, daniel@ffwll.ch, jani.nikula@linux.intel.com, jhubbard@nvidia.com, joonas.lahtinen@linux.intel.com, jrdr.linux@gmail.com, linux-mm@kvack.org, matthew.auld@intel.com, mm-commits@vger.kernel.org, rodrigo.vivi@intel.com, torvalds@linux-foundation.org, tvrtko.ursulin@intel.com, willy@infradead.org From: John Hubbard Subject: drm/i915: convert get_user_pages() --> pin_user_pages() This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Link: http://lkml.kernel.org/r/20200519002124.2025955-5-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Chris Wilson Cc: Souptick Joarder Cc: Matthew Wilcox Cc: Jani Nikula Cc: "Joonas Lahtinen" Cc: Rodrigo Vivi Cc: David Airlie Cc: Daniel Vetter Cc: Tvrtko Ursulin Cc: Matthew Auld Signed-off-by: Andrew Morton --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 22 ++++++++++-------- 1 file changed, 13 insertions(+), 9 deletions(-) --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c~drm-i915-convert-get_user_pages-pin_user_pages +++ a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -471,7 +471,7 @@ __i915_gem_userptr_get_pages_worker(stru down_read(&mm->mmap_sem); locked = 1; } - ret = get_user_pages_remote + ret = pin_user_pages_remote (work->task, mm, obj->userptr.ptr + pinned * PAGE_SIZE, npages - pinned, @@ -507,7 +507,7 @@ __i915_gem_userptr_get_pages_worker(stru } mutex_unlock(&obj->mm.lock); - release_pages(pvec, pinned); + unpin_user_pages(pvec, pinned); kvfree(pvec); i915_gem_object_put(obj); @@ -564,6 +564,7 @@ static int i915_gem_userptr_get_pages(st struct sg_table *pages; bool active; int pinned; + unsigned int gup_flags = 0; /* If userspace should engineer that these pages are replaced in * the vma between us binding this page into the GTT and completion @@ -606,11 +607,14 @@ static int i915_gem_userptr_get_pages(st * * We may or may not care. */ - if (pvec) /* defer to worker if malloc fails */ - pinned = __get_user_pages_fast(obj->userptr.ptr, - num_pages, - !i915_gem_object_is_readonly(obj), - pvec); + if (pvec) { + /* defer to worker if malloc fails */ + if (!i915_gem_object_is_readonly(obj)) + gup_flags |= FOLL_WRITE; + pinned = pin_user_pages_fast_only(obj->userptr.ptr, + num_pages, gup_flags, + pvec); + } } active = false; @@ -628,7 +632,7 @@ static int i915_gem_userptr_get_pages(st __i915_gem_userptr_set_active(obj, true); if (IS_ERR(pages)) - release_pages(pvec, pinned); + unpin_user_pages(pvec, pinned); kvfree(pvec); return PTR_ERR_OR_ZERO(pages); @@ -683,7 +687,7 @@ i915_gem_userptr_put_pages(struct drm_i9 } mark_page_accessed(page); - put_page(page); + unpin_user_page(page); } obj->mm.dirty = false; _