Re: Sluggish performance after resume//Re: Bug Report - [Acer Aspire V5-122P] Unable to adjust screen brightness

[Ben Widawsky <ben@bwidawsk.net>]

On Tue, Jun 10, 2014 at 01:33:51PM +0800, Aaron Lu wrote:
> +Ben Widawsky & Daniel Vetter
>  
> On 06/09/2014 03:38 PM, Lewis Toohey wrote:
> > On 3 June 2014 02:22, Aaron Lu <aaron.lu@intel.com> wrote:
> >> On 05/30/2014 09:12 PM, Lewis Toohey wrote:
> >>> Aaron
> >>>
> >>> I am in the process of performing this bisection, however, I need a
> >>> bit of advice.
> >>>
> >>> I have got a mix of results following suspend right through from (i)
> >>> system reboot; (ii) "low graphics mode" error; (iii) restore but
> >>> sluggish performance; and (iv) restore but *very* sluggish
> >>> performance.
> >>
> >> Is the sluggish performance experienced with a GUI environment?
> >>
> >>>
> >>> What should qualify as a bad commit? Anything other than a "perfect" restore?
> >>
> >> I think ii/iii/iv all qualify as bad, if there is no such problem
> >> in previous kernels. And yes, a perfect restore is expected, assume
> >> the system is able to do a perfect restore with old kernels.
> >>
> >> Thanks,
> >> Aaron
> >>
> >>>
> >>> Many thanks
> >>>
> > 
> > Hi Aaron
> > 
> > Firstly, yes the sluggish performance I was referring to is
> > experienced in the GUI environment. Jerky graphics and CPU fan appears
> > to max out and stay there. Old kernels (e.g. the Ubuntu default
> > kernel) do not do this and just restore perfectly.
> > 
> > I have completed the bisect as requested. Please find the full log
> > below. I am slightly unconvinced, as building the previous commit in
> > the log still seems to have the same problem, however, that commit is
> > a "merge" and I don't really know what this means.
> > 
> > Many thanks
> > 
> > Bisect Log:
> > git bisect start
> > # good: [455c6fdbd219161bd09b1165f11699d6d73de11c] Linux 3.14
> > git bisect good 455c6fdbd219161bd09b1165f11699d6d73de11c
> > # bad: [c9eaa447e77efe77b7fa4c953bd62de8297fd6c5] Linux 3.15-rc1
> > git bisect bad c9eaa447e77efe77b7fa4c953bd62de8297fd6c5
> > # good: [cd6362befe4cc7bf589a5236d2a780af2d47bcc9] Merge
> > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
> > git bisect good cd6362befe4cc7bf589a5236d2a780af2d47bcc9
> > # good: [d2b150d0647e055d7a71b1c33140280550b27dd6] Merge tag 'sh-3.15'
> > of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
> > git bisect good d2b150d0647e055d7a71b1c33140280550b27dd6
> > # good: [5fb6b953bb7aa86a9c8ea760934982cedc45c52b]
> > include/linux/syscalls.h: add sys_renameat2() prototype
> > git bisect good 5fb6b953bb7aa86a9c8ea760934982cedc45c52b
> > # bad: [ffddc5fd19b219f557fd4a81168ce8784a4faced] fs/ncpfs/dir.c: fix
> > indenting in ncp_lookup()
> > git bisect bad ffddc5fd19b219f557fd4a81168ce8784a4faced
> > # bad: [978c6050165bba52eab7ef3581d447eb215def77] Merge branch
> > 'drm-docs' of ssh://people.freedesktop.org/~danvet/drm into drm-next
> > git bisect bad 978c6050165bba52eab7ef3581d447eb215def77
> > # bad: [262de1453184f65e5ccfe45790f93d41f7339d49] drm/i915: Directly
> > return the vma from bind_to_vm
> > git bisect bad 262de1453184f65e5ccfe45790f93d41f7339d49
> > # bad: [031994ee8dedfa69d3a7caa43e93f3c282bc38f9] drm/i915: Implement
> > WaIncreaseL3CreditsForVLVB0:vlv
> > git bisect bad 031994ee8dedfa69d3a7caa43e93f3c282bc38f9
> > # bad: [f72d21eddfa900bfa2674195dcc0203e18d0cc62] drm/i915: Place the
> > Global GTT VM first in the list of VM
> > git bisect bad f72d21eddfa900bfa2674195dcc0203e18d0cc62
> > # bad: [d6660add648d10e7e35085d8c7d2653e0f9f61b7] drm/i915: Generalize
> > PPGTT init
> > git bisect bad d6660add648d10e7e35085d8c7d2653e0f9f61b7
> > # bad: [b731d33d05dd5ce6b387cbadb0d9d24cb3732b40] drm/i915: relax
> > context alignment
> > git bisect bad b731d33d05dd5ce6b387cbadb0d9d24cb3732b40
> > # bad: [a7b910789f77afa40ae0816d22339e9d25723c6e] drm/i915: Add vm to
> > error BO capture
> > git bisect bad a7b910789f77afa40ae0816d22339e9d25723c6e
> > # bad: [6e164c3382314a1f63526fa7a4322a17318d0e32] drm/i915: Allow ggtt
> > lookups to not WARN
> > git bisect bad 6e164c3382314a1f63526fa7a4322a17318d0e32
> > # bad: [6f425321e02a1b6c5e90b70f8fab7c140fcaeefb] drm/i915: Don't
> > unconditionally try to deref aliasing ppgtt
> > git bisect bad 6f425321e02a1b6c5e90b70f8fab7c140fcaeefb
> > # bad: [e178f7057b81c87a7ceaae0ca204487b6f7eedcf] drm/i915: Provide
> > PDP updates via MMIO
> > git bisect bad e178f7057b81c87a7ceaae0ca204487b6f7eedcf
> > # first bad commit: [e178f7057b81c87a7ceaae0ca204487b6f7eedcf]
> > drm/i915: Provide PDP updates via MMIO
> > 
> 
> The commit looks like related, I've added the commit author.
> 
> Ben,
> Do you have any suggestions? Does the above commit have any chance of
> causing sluggish performance problem after a resume?
> 
> Thanks,
> Aaron

What this comment actually does is use MMIO writes for the page tables
after a GPU hang/reset. (What a poorly named commit message).

Can you please provide the full dmesg with the drm.debug=0x2?

-- 
Ben Widawsky, Intel Open Source Technology Center