From: Michel Thierry <michel.thierry@intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>, intel-gfx@lists.freedesktop.org
Subject: Re: [RFC] drm/i915: Handle E2BIG error in i915_gem_fault
Date: Wed, 9 Sep 2015 17:53:57 +0100 [thread overview]
Message-ID: <55F06425.8020604@intel.com> (raw)
In-Reply-To: <20150909103319.GC32324@nuc-i3427.alporthouse.com>
On 9/9/2015 11:33 AM, Chris Wilson wrote:
> On Wed, Sep 09, 2015 at 11:29:52AM +0100, Michel Thierry wrote:
>> i915_gem_object_bind_to_vm returns -E2BIG when the user tries to bind an
>> object larger than the aperture, but i915_gem_fault does not handle this
>> return code:
>>
>> [501906.530985] gem_mmap_gtt: starting subtest big-bo-tiledX
>> [501906.541992] gem_mmap_gtt (22362): drop_caches: 3
>> [501906.610774] WARNING: CPU: 2 PID: 22362 at
>> drivers/gpu/drm/i915/i915_gem.c:1880 i915_gem_fault+0x24f/0x470 [i915]()
>> [501906.623568] unhandled error in i915_gem_fault: -7
>> [501906.825115] Call Trace:
>> [501906.830322] [<ffffffff8178ffcc>] dump_stack+0x45/0x57
>> [501906.838589] [<ffffffff810759aa>] warn_slowpath_common+0x8a/0xc0
>> [501906.847846] [<ffffffff81075a26>] warn_slowpath_fmt+0x46/0x50
>> [501906.856776] [<ffffffffc079591f>] i915_gem_fault+0x24f/0x470 [i915]
>> [501906.866276] [<ffffffff8119e11d>] __do_fault+0x3d/0xa0
>> [501906.874464] [<ffffffff81068cc0>] ? pte_alloc_one+0x30/0x50
>> [501906.883169] [<ffffffff811a26a7>] handle_mm_fault+0xe27/0x1810
>> [501906.892202] [<ffffffff81306e8a>] ? security_mmap_file+0xca/0xe0
>> [501906.900389] [<ffffffff811fb6ad>] ? do_vfs_ioctl+0x2cd/0x4b0
>> [501906.908143] [<ffffffff81063ada>] __do_page_fault+0x19a/0x430
>> [501906.916024] [<ffffffff81063d92>] do_page_fault+0x22/0x30
>> [501906.923532] [<ffffffff81799248>] page_fault+0x28/0x30
>>
>> RFC about the error code that should be returned by i915_gem_fault.
>
> There are two fixes here, change E2BIG to ENOSPC. The differentiate is
> painful to all consumers (and missing in userspace).
I'll change the return code in gem_object_bind_to_vm instead.
>
> The second is that gem_fault was supposed to be fixed to handle it and
> sigbus is the legimate error for that case (not enomem/sigsegv).
These subtests use objs tiling x/y, so the driver won't use partial views.
Should it be better if i915_gem_mmap_gtt checks for this (obj size
bigger than apperture and some tiling mode), and return an error at that
point? Instead of waiting for the sigbus error in gem_fault.
-Michel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2015-09-09 16:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-09 10:29 [RFC] drm/i915: Handle E2BIG error in i915_gem_fault Michel Thierry
2015-09-09 10:33 ` Chris Wilson
2015-09-09 16:53 ` Michel Thierry [this message]
2015-09-09 17:44 ` Chris Wilson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55F06425.8020604@intel.com \
--to=michel.thierry@intel.com \
--cc=chris@chris-wilson.co.uk \
--cc=intel-gfx@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.