Chris Wilson dd345efe8a drm/i915/gt: Mark up racy check of breadcrumb irq enabled
We control b->irq_enabled inside the b->irq_lock, but we check before
entering the spinlock whether or not the interrupt is currently
unmasked.

[ 1511.735208] BUG: KCSAN: data-race in __intel_breadcrumbs_disarm_irq [i915] / intel_engine_disarm_breadcrumbs [i915]
[ 1511.735231]
[ 1511.735242] write to 0xffff8881f75fc214 of 1 bytes by interrupt on cpu 2:
[ 1511.735440]  __intel_breadcrumbs_disarm_irq+0x4b/0x160 [i915]
[ 1511.735635]  signal_irq_work+0x337/0x710 [i915]
[ 1511.735652]  irq_work_run_list+0xd7/0x110
[ 1511.735666]  irq_work_run+0x1d/0x50
[ 1511.735681]  smp_irq_work_interrupt+0x21/0x30
[ 1511.735701]  irq_work_interrupt+0xf/0x20
[ 1511.735722]  __do_softirq+0x6f/0x206
[ 1511.735736]  irq_exit+0xcd/0xe0
[ 1511.735756]  do_IRQ+0x44/0xc0
[ 1511.735773]  ret_from_intr+0x0/0x1c
[ 1511.735787]  schedule+0x0/0xb0
[ 1511.735803]  worker_thread+0x194/0x670
[ 1511.735823]  kthread+0x19a/0x1e0
[ 1511.735837]  ret_from_fork+0x1f/0x30
[ 1511.735848]
[ 1511.735867] read to 0xffff8881f75fc214 of 1 bytes by task 432 on cpu 1:
[ 1511.736068]  intel_engine_disarm_breadcrumbs+0x22/0x80 [i915]
[ 1511.736263]  __engine_park+0x107/0x5d0 [i915]
[ 1511.736453]  ____intel_wakeref_put_last+0x44/0x90 [i915]
[ 1511.736648]  __intel_wakeref_put_last+0x5a/0x70 [i915]
[ 1511.736842]  intel_context_exit_engine+0xf2/0x100 [i915]
[ 1511.737044]  i915_request_retire+0x6b2/0x770 [i915]
[ 1511.737244]  retire_requests+0x7a/0xd0 [i915]
[ 1511.737438]  intel_gt_retire_requests_timeout+0x3a7/0x6f0 [i915]
[ 1511.737633]  i915_drop_caches_set+0x1e7/0x260 [i915]
[ 1511.737650]  simple_attr_write+0xfa/0x110
[ 1511.737665]  full_proxy_write+0x94/0xc0
[ 1511.737679]  __vfs_write+0x4b/0x90
[ 1511.737697]  vfs_write+0xfc/0x280
[ 1511.737718]  ksys_write+0x78/0x100
[ 1511.737732]  __x64_sys_write+0x44/0x60
[ 1511.737751]  do_syscall_64+0x6e/0x2c0
[ 1511.737769]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200408092916.5355-1-chris@chris-wilson.co.uk
2020-04-08 13:40:07 +01:00
2020-02-13 16:30:22 +01:00
2020-01-18 09:19:18 -05:00
2020-02-16 13:16:59 -08:00

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.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%