GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation. As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.
The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory. So
this is rather misleading and hard to evaluate for any benefits.
I have checked some random users and none of them has added the flag
with a specific justification. I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring. This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.
I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL. Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.
I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.
This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic. It
seems to be a heuristic without any measured advantage for most (if not
all) its current users. The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers. So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.
[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ defines to the UAPI
as a convenience.
Ideally the DRM_ROTATE_ and DRM_REFLECT_ property ids are looked up
through the atomic API, but realizing that userspace is likely to take
shortcuts and assume that the enum values are what is sent over the
wire.
As a result these defines are provided purely as a convenience to
userspace applications.
Changes since v3:
- Switched away from past tense in comments
- Add define name change to previously mis-spelled DRM_REFLECT_X comment
- Improved the comment for the DRM_MODE_REFLECT_<axis> comment
Changes since v2:
- Changed define prefix from DRM_MODE_PROP_ to DRM_MODE_
- Fix compilation errors
- Changed comment formatting
- Deduplicated comment lines
- Clarified DRM_MODE_PROP_REFLECT_ comment
Changes since v1:
- Moved defines from drm.h to drm_mode.h
- Changed define prefix from DRM_ to DRM_MODE_PROP_
- Updated uses of the defines to the new prefix
- Removed include from drm_rect.c
- Stopped using the BIT() macro
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519205017.23307-2-robert.foss@collabora.com
There are new iterator macros that annotate whether the new or old
state should be used. This is better than using a state that depends on
whether it's called before or after swap. For clarity, also rename the
variables from $obj_state to (old,new)_$obj_state as well.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1487256430-7625-6-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This is a straightforward conversion that converts all the users of
get_existing_state in atomic core to use get_old_state or get_new_state
Changes since v1:
- Fix using the wrong state in drm_atomic_helper_update_legacy_modeset_state.
Changes since v2:
- Use the correct state in disable_outputs()
Changes since v3:
- Rebase for link status training.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/df91a9f9-005e-bcbd-1f74-03c38e1e21dd@linux.intel.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
I just learned that &struct_name.member_name works and looks pretty
even. It doesn't (yet) link to the member directly though, which would
be really good for big structures or vfunc tables (where the
per-member kerneldoc tends to be long).
Also some minor drive-by polish where it makes sense, I read a lot
of docs ...
v2: Review from Eric.
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170125062657.19270-4-daniel.vetter@ffwll.ch
Now that all drivers have been converted over to the per-plane rotation
property, we can just nuke the global rotation property.
v2: Rebase due to BIT(),__builtin_ffs() & co.
Deal with superfluous code shuffling
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477077768-4274-4-git-send-email-ville.syrjala@linux.intel.com
Not all planes on the system may support the same rotations/reflections,
so make it possible to create a separate property for each plane.
This way userspace gets told exactly which rotations/reflections are
possible for each plane.
v2: Add drm_plane_create_rotation_property() helper
v3: Drop the BIT(), __builtin_ffs(x) - 1,
Moar WARNs for bad parameters
Deal with superfluous code shuffling
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474907460-10717-4-git-send-email-ville.syrjala@linux.intel.com
Try to spec a bit more precisely how they all fit together, now that
at least the code is for all the additional properties is in one
place.
Also remove the entries for the standardized properties from the
table, because that thing is supremely unmaintaineable.
v2: Fix typos Sean spotted.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-4-git-send-email-daniel.vetter@ffwll.ch
Imo zpos, rotatation, blending eq (once we have it) and all that
should be in drm_blend.c, since those are all about how exactly the
pixels are rendered onto the CRTC's visible area. Also noticed that
one exported function accidentally ended up in drm_crtc_internal.h,
move it to the right place too.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-3-git-send-email-daniel.vetter@ffwll.ch
drm/drm_blend.c:207:5: warning: symbol 'drm_atomic_normalize_zpos' was not declared. Should it be static?
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474292035-15695-3-git-send-email-ville.syrjala@linux.intel.com
There's not much point in kerneldoc if it's not included:
- It won't show up in the pretty html pages.
- The comments itself won't get parsed, which means 0day won't pick up
changes, resulting in stale docs fast.
Also, uapi really should be core, not helpers, so move drm_blend.c to
that. That also means that the zpos normilize function loses it's
helper status (and we might as well call it always). For that,
EXPORT_SYMBOL. Just spotted while integrating docs and noticing that
one was missing.
With sphinx there's really no excuse any more to not build the docs
and make sure it's all nice!
$ make DOCBOOKS="" htmldocs
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-15-git-send-email-daniel.vetter@ffwll.ch
version 8:
- move drm_blend.o from drm-y to drm_kms_helper-y to avoid
EXPORT_SYMBOL(drm_atomic_helper_normalize_zpos)
- remove dead function declarations in drm_crtc.h
version 7:
- remove useless EXPORT_SYMBOL()
- better z-order wording in Documentation
version 6:
- add zpos in gpu documentation file
- merge Ville patch about zpos initial value and API improvement.
I have split Ville patch between zpos core and drivers
version 5:
- remove zpos range check and comeback to 0 to N-1
normalization algorithm
version 4:
- make sure that normalized zpos value is stay
in the defined property range and warn user if not
This patch adds support for generic plane's zpos property property with
well-defined semantics:
- added zpos properties to plane and plane state structures
- added helpers for normalizing zpos properties of given set of planes
- well defined semantics: planes are sorted by zpos values and then plane
id value if zpos equals
Normalized zpos values are calculated automatically when generic
muttable zpos property has been initialized. Drivers can simply use
plane_state->normalized_zpos in their atomic_check and/or plane_update
callbacks without any additional calls to DRM core.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Compare to Marek's original patch zpos property is now specific to each
plane and no more to the core.
Normalize function take care of the range of per plane defined range
before set normalized_zpos.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: vincent.abriou@st.com
Cc: fabien.dessenne@st.com
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Michal Hocko