Chris Wilson chris@chris-wilson.co.uk writes:

As the error capture will compress user buffers as directed to by the user, it can take an arbitrary amount of time and space. Break up the compression loops with a call to cond_resched(), that will allow other processes to schedule (avoiding the soft lockups) and also serve as a warning should we try to make this loop atomic in the future.

Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Mika Kuoppala mika.kuoppala@linux.intel.com Cc: stable@vger.kernel.org

Reviewed-by: Mika Kuoppala mika.kuoppala@linux.intel.com

---

drivers/gpu/drm/i915/i915_gpu_error.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 6a3a2ce0b394..6551ff04d5a6 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -311,6 +311,8 @@ static int compress_page(struct i915_vma_compress *c, if (zlib_deflate(zstream, Z_NO_FLUSH) != Z_OK) return -EIO;

• cond_resched();
  

  } while (zstream->avail_in);

/* Fallback to uncompressed if we increase size? */ @@ -397,6 +399,7 @@ static int compress_page(struct i915_vma_compress *c, if (!(wc && i915_memcpy_from_wc(ptr, src, PAGE_SIZE))) memcpy(ptr, src, PAGE_SIZE); dst->pages[dst->page_count++] = ptr;

• cond_resched();

return 0; } -- 2.20.1