From 7d5553147613b50149238ac1385c60e5c7cacb34 Mon Sep 17 00:00:00 2001

From: Chris Wilson <chris@chris-wilson.co.uk>

Date: Wed, 16 Sep 2020 10:00:58 +0100

Subject: [PATCH] drm/i915: Break up error capture compression loops with cond_resched()

Git-commit: 7d5553147613b50149238ac1385c60e5c7cacb34

Patch-mainline: v5.10-rc1

No-fix: 293f43c80c0027ff9299036c24218ac705ce584e

References: git-fixes

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.

Testcase: igt/gem_exec_capture/many-*

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>

Link: https://patchwork.freedesktop.org/patch/msgid/20200916090059.3189-2-chris@chris-wilson.co.uk

(cherry picked from commit 293f43c80c0027ff9299036c24218ac705ce584e)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/gpu/drm/i915/i915_gpu_error.c |    3 +++

 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/i915/i915_gpu_error.c

+++ b/drivers/gpu/drm/i915/i915_gpu_error.c

@@ -268,6 +268,8 @@ static int compress_page(struct compress

 		if (zlib_deflate(zstream, Z_NO_FLUSH) != Z_OK)

 			return -EIO;

+

+		cond_resched();

 	} while (zstream->avail_in);

 	/* Fallback to uncompressed if we increase size? */

@@ -347,6 +349,7 @@ static int compress_page(struct compress

 	if (!i915_memcpy_from_wc(ptr, src, PAGE_SIZE))

 		memcpy(ptr, src, PAGE_SIZE);

 	dst->pages[dst->page_count++] = ptr;

+	cond_resched();

 	return 0;

 }