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: be1cb55a07 ("drm/i915/gt: Keep a no-frills swappable copy of the default context state")
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Venkata Ramana Nayana <venkata.ramana.nayana@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.8+
Link: https://patchwork.freedesktop.org/patch/msgid/20201127120718.454037-161-matthew.auld@intel.com
(cherry picked from commit a9d71f76cc)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Venkata Ramana Nayana 2020-11-27 12:07:16 +00:00 committed by Rodrigo Vivi
parent 2bfdf30246
commit 78b2eb8a1f
1 changed files with 5 additions and 2 deletions

View File

@ -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);