From a9d71f76ccfd309f3bd5f7c9b60e91a4decae792 Mon Sep 17 00:00:00 2001 From: Venkata Ramana Nayana Date: Fri, 27 Nov 2020 12:07:16 +0000 Subject: [PATCH] drm/i915/gt: Retain default context state across shrinking As we use a shmemfs file to hold the context state, when not in use it may be swapped out, such as across suspend. Since we wrote into the shmemfs without marking the pages as dirty, the contents may be dropped instead of being written back to swap. On re-using the shmemfs file, such as creating a new context after resume, the contents of that file were likely garbage and so the new context could then hang the GPU. Simply mark the page as being written when copying into the shmemfs file, and it the new contents will be retained across swapout. Fixes: be1cb55a07bf ("drm/i915/gt: Keep a no-frills swappable copy of the default context state") Cc: Sudeep Dutt Cc: Matthew Auld Cc: Tvrtko Ursulin Cc: Ramalingam C Signed-off-by: CQ Tang Signed-off-by: Venkata Ramana Nayana Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Cc: # v5.8+ Link: https://patchwork.freedesktop.org/patch/msgid/20201127120718.454037-161-matthew.auld@intel.com --- drivers/gpu/drm/i915/gt/shmem_utils.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c index f011ea42487e1..463af675faddb 100644 --- a/drivers/gpu/drm/i915/gt/shmem_utils.c +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c @@ -103,10 +103,13 @@ static int __shmem_rw(struct file *file, loff_t off, return PTR_ERR(page); vaddr = kmap(page); - if (write) + if (write) { memcpy(vaddr + offset_in_page(off), ptr, this); - else + set_page_dirty(page); + } else { memcpy(ptr, vaddr + offset_in_page(off), this); + } + mark_page_accessed(page); kunmap(page); put_page(page); -- 2.30.2