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Daniel Vetter 9ec8795e7d drm/i915: Drop __rcu from gem_context->vm
It's been invariant since

    commit ccbc1b9794
    Author: Jason Ekstrand <jason@jlekstrand.net>
    Date:   Thu Jul 8 10:48:30 2021 -0500

        drm/i915/gem: Don't allow changing the VM on running contexts (v4)

this just completes the deed. I've tried to split out prep work for
more careful review as much as possible, this is what's left:

- get_ppgtt gets simplified since we don't need to grab a temporary
  reference - we can rely on the temporary reference for the gem_ctx
  while we inspect the vm. The new vm_id still needs a full
  i915_vm_open ofc. This also removes the final caller of context_get_vm_rcu

- A pile of selftests can now just look at ctx->vm instead of
  rcu_dereference_protected( , true) or similar things.

- All callers of i915_gem_context_vm also disappear.

- I've changed the hugepage selftest to set scrub_64K without any
  locking, because when we inspect that setting we're also not taking
  any locks either. It works because it's a selftests that's careful
  (single threaded gives you nice ordering) and not a live driver
  where races can happen from anywhere.

These can only be split up further if we have some intermediate state
with a bunch more rcu_dereference_protected(ctx->vm, true), just to
shut up lockdep and sparse.

The conversion to __rcu happened in

commit a4e7ccdac3
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Oct 4 14:40:09 2019 +0100

    drm/i915: Move context management under GEM

Note that we're not breaking the actual bugfix in there: The real
bugfix is pushing the i915_vm_relase onto a separate worker, to avoid
locking inversion issues. The rcu conversion was just thrown in for
entertainment value on top (no vm lookup isn't even close to anything
that's a hotpath where removing the single spinlock can be measured).

v2: Rebase over the change to move the i915_vm_put() into
i915_gem_context_release().

v3: Trivial conflict against repainted shed.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902142057.929669-9-daniel.vetter@ffwll.ch
2021-09-06 11:11:32 +02:00
Documentation drm/doc/rfc: drop lmem uapi section 2021-08-11 16:18:15 +02:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch Two fixes: 2021-07-11 11:17:57 -07:00
block block-5.14-2021-07-08 2021-07-09 12:05:33 -07:00
certs Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-07-09 11:00:44 -07:00
drivers drm/i915: Drop __rcu from gem_context->vm 2021-09-06 11:11:32 +02:00
fs 13 cifs/smb3 fixes. Most are to address minor issues pointed out by Coverity. Also includes a packet signing enhancement and mount improvement 2021-07-10 12:04:58 -07:00
include drm/ttm, drm/i915: Update ttm_move_memcpy for async use 2021-08-25 16:05:47 +02:00
init Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
ipc Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
kernel Two fixes: 2021-07-11 11:17:57 -07:00
lib mm/page_alloc: Revert pahole zero-sized workaround 2021-07-10 16:09:39 -07:00
mm mm/rmap: try_to_migrate() skip zone_device !device_private 2021-07-11 15:05:15 -07:00
net We have new filesystem client metrics for reporting I/O sizes from 2021-07-09 09:52:13 -07:00
samples VFIO update for v5.14-rc1 2021-07-03 11:49:33 -07:00
scripts Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
security asm-generic/unaligned: Unify asm/unaligned.h around struct helper 2021-07-02 12:43:40 -07:00
sound sound fixes for 5.14-rc1 2021-07-09 11:40:26 -07:00
tools perf tools changes for v5.14: 2nd batch 2021-07-11 10:54:24 -07:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap m68k updates for v5.14 2021-06-28 14:01:03 -07:00
COPYING
CREDITS MAINTAINERS: move Murali Karicheri to credits 2021-04-29 15:47:30 -07:00
Kbuild
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS SCSI misc on 20210711 2021-07-11 10:59:53 -07:00
Makefile Linux 5.14-rc1 2021-07-11 15:07:40 -07:00
README

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.