The largest possible order is (63-PAGE_SHIFT), given that our min chunk
size is PAGE_SIZE. With that we should only need at most 6 bits to
represent all possible orders, giving us back 4 bits for other potential
uses. Include a simple selftest to verify this.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210126103019.177622-1-matthew.auld@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
igt_mm_config() calls ilog2() on the (pseudo)random 21-bit number
s>>12. Once in 2 million seeds, this is zero and ilog2 summons
the nasal demons.
There was an attempt to handle this case with a max(), but that's
too late; ms could already be something bizarre.
Given that the low 12 bits of s and ms are always zero, it's a lot
simpler just to divide them by 4096, then everything fits into 32
bits, and we can easily generate a random number 1 <= s <= 0x1fffff.
Fixes: 14d1b9a624 ("drm/i915: buddy allocator")
Signed-off-by: George Spelvin <lkml@sdf.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200325192429.GA8865@SDF.ORG
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 21118e8e56)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Depending on RNG we might try to fill an 8G region for every possible
order, using the smallest possible chunk size of 4K, which seems to be
very slow. Try to remedy the situation by adding an overall timeout for
the test, while also selecting each order level in a random fashion.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1310
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305204711.217783-2-matthew.auld@intel.com
Let the scheduler have a breather in between passes of the longer buddy
tests. Important if we are running under kasan etc and this takes far
longer than usual!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190829170848.969-1-chris@chris-wilson.co.uk
Dan reported the following static checker warning:
drivers/gpu/drm/i915/selftests/i915_buddy.c:670 igt_buddy_alloc_range()
error: we previously assumed 'block' could be null (see line 665)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190815103210.11802-1-matthew.auld@intel.com
Simple buddy allocator. We want to allocate properly aligned
power-of-two blocks to promote usage of huge-pages for the GTT, so 64K,
2M and possibly even 1G. While we do support allocating stuff at a
specific offset, it is more intended for preallocating portions of the
address space, say for an initial framebuffer, for other uses drm_mm is
probably a much better fit. Anyway, hopefully this can all be thrown
away if we eventually move to having the core MM manage device memory.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809202926.14545-2-matthew.auld@intel.com
