Re: [PATCH v2 00/21] Refine memblock API

[Adam Ford <aford173@gmail.com>]

On Wed, Oct 2, 2019 at 2:36 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> Hi Adam,
>
> On Tue, Oct 01, 2019 at 07:14:13PM -0500, Adam Ford wrote:
> > On Sun, Sep 29, 2019 at 8:33 AM Adam Ford <aford173@gmail.com> wrote:
> > >
> > > I am attaching two logs.  I now the mailing lists will be unhappy, but
> > >  don't want to try and spam a bunch of log through the mailing liast.
> > > The two logs show the differences between the working and non-working
> > > imx6q 3D accelerator when trying to run a simple glmark2-es2-drm demo.
> > >
> > > The only change between them is the 2 line code change you suggested.
> > >
> > > In both cases, I have cma=128M set in my bootargs.  Historically this
> > > has been sufficient, but cma=256M has not made a difference.
> > >
> >
> > Mike any suggestions on how to move forward?
> > I was hoping to get the fixes tested and pushed before 5.4 is released
> > if at all possible
>
> I have a fix (below) that kinda restores the original behaviour, but I
> still would like to double check to make sure it's not a band aid and I
> haven't missed the actual root cause.
>
> Can you please send me your device tree definition and the output of
>
> cat /sys/kernel/debug/memblock/memory
>
> and
>
> cat /sys/kernel/debug/memblock/reserved
>
> Thanks!
>

Before the patch:

# cat /sys/kernel/debug/memblock/memory
   0: 0x10000000..0x8fffffff
# cat /sys/kernel/debug/memblock/reserved
   0: 0x10004000..0x10007fff
   1: 0x10100000..0x11ab141f
   2: 0x1fff1000..0x1fffcfff
   3: 0x2ee40000..0x2ef53fff
   4: 0x2ef56940..0x2ef56c43
   5: 0x2ef56c48..0x2fffefff
   6: 0x2ffff0c0..0x2ffff4d8
   7: 0x2ffff500..0x2ffff55f
   8: 0x2ffff580..0x2ffff703
   9: 0x2ffff740..0x2ffff918
  10: 0x2ffff940..0x2ffff9cf
  11: 0x2ffffa00..0x2ffffa0f
  12: 0x2ffffa40..0x2ffffa43
  13: 0x2ffffa80..0x2ffffad5
  14: 0x2ffffb00..0x2ffffb55
  15: 0x2ffffb80..0x2ffffbd5
  16: 0x2ffffc00..0x2ffffc4e
  17: 0x2ffffc50..0x2ffffc6a
  18: 0x2ffffc6c..0x2ffffce6
  19: 0x2ffffce8..0x2ffffd02
  20: 0x2ffffd04..0x2ffffd1e
  21: 0x2ffffd20..0x2ffffd3a
  22: 0x2ffffd3c..0x2ffffd56
  23: 0x2ffffd58..0x2ffffe30
  24: 0x2ffffe34..0x2ffffe4c
  25: 0x2ffffe50..0x2ffffe68
  26: 0x2ffffe6c..0x2ffffe84
  27: 0x2ffffe88..0x2ffffea0
  28: 0x2ffffea4..0x2ffffebc
  29: 0x2ffffec0..0x2ffffedf
  30: 0x2ffffee4..0x2ffffefc
  31: 0x2fffff00..0x2fffff13
  32: 0x2fffff28..0x2fffff4b
  33: 0x2fffff50..0x2fffff84
  34: 0x2fffff88..0x3fffffff


After the patch:
# cat /sys/kernel/debug/memblock/memory
   0: 0x10000000..0x8fffffff
# cat /sys/kernel/debug/memblock/reserved
   0: 0x10004000..0x10007fff
   1: 0x10100000..0x11ab141f
   2: 0x1fff1000..0x1fffcfff
   3: 0x3eec0000..0x3efd3fff
   4: 0x3efd6940..0x3efd6c43
   5: 0x3efd6c48..0x3fffbfff
   6: 0x3fffc0c0..0x3fffc4d8
   7: 0x3fffc500..0x3fffc55f
   8: 0x3fffc580..0x3fffc703
   9: 0x3fffc740..0x3fffc918
  10: 0x3fffc940..0x3fffc9cf
  11: 0x3fffca00..0x3fffca0f
  12: 0x3fffca40..0x3fffca43
  13: 0x3fffca80..0x3fffca83
  14: 0x3fffcac0..0x3fffcb15
  15: 0x3fffcb40..0x3fffcb95
  16: 0x3fffcbc0..0x3fffcc15
  17: 0x3fffcc28..0x3fffcc72
  18: 0x3fffcc74..0x3fffcc8e
  19: 0x3fffcc90..0x3fffcd0a
  20: 0x3fffcd0c..0x3fffcd26
  21: 0x3fffcd28..0x3fffcd42
  22: 0x3fffcd44..0x3fffcd5e
  23: 0x3fffcd60..0x3fffcd7a
  24: 0x3fffcd7c..0x3fffce54
  25: 0x3fffce58..0x3fffce70
  26: 0x3fffce74..0x3fffce8c
  27: 0x3fffce90..0x3fffcea8
  28: 0x3fffceac..0x3fffcec4
  29: 0x3fffcec8..0x3fffcee0
  30: 0x3fffcee4..0x3fffcefc
  31: 0x3fffcf00..0x3fffcf1f
  32: 0x3fffcf28..0x3fffcf53
  33: 0x3fffcf68..0x3fffcf8b
  34: 0x3fffcf90..0x3fffcfac
  35: 0x3fffcfb0..0x3fffffff
  36: 0x80000000..0x8fffffff

> From 06529f861772b7dea2912fc2245debe4690139b8 Mon Sep 17 00:00:00 2001
> From: Mike Rapoport <rppt@linux.ibm.com>
> Date: Wed, 2 Oct 2019 10:14:17 +0300
> Subject: [PATCH] mm: memblock: do not enforce current limit for memblock_phys*
>  family
>
> Until commit 92d12f9544b7 ("memblock: refactor internal allocation
> functions") the maximal address for memblock allocations was forced to
> memblock.current_limit only for the allocation functions returning virtual
> address. The changes introduced by that commit moved the limit enforcement
> into the allocation core and as a result the allocation functions returning
> physical address also started to limit allocations to
> memblock.current_limit.
>
> This caused breakage of etnaviv GPU driver:
>
> [    3.682347] etnaviv etnaviv: bound 130000.gpu (ops gpu_ops)
> [    3.688669] etnaviv etnaviv: bound 134000.gpu (ops gpu_ops)
> [    3.695099] etnaviv etnaviv: bound 2204000.gpu (ops gpu_ops)
> [    3.700800] etnaviv-gpu 130000.gpu: model: GC2000, revision: 5108
> [    3.723013] etnaviv-gpu 130000.gpu: command buffer outside valid
> memory window
> [    3.731308] etnaviv-gpu 134000.gpu: model: GC320, revision: 5007
> [    3.752437] etnaviv-gpu 134000.gpu: command buffer outside valid
> memory window
> [    3.760583] etnaviv-gpu 2204000.gpu: model: GC355, revision: 1215
> [    3.766766] etnaviv-gpu 2204000.gpu: Ignoring GPU with VG and FE2.0
>
> Restore the behaviour of memblock_phys* family so that these functions will
> not enforce memblock.current_limit.
>

This fixed the issue.  Thank you

Tested-by: Adam Ford <aford173@gmail.com> #imx6q-logicpd

> Fixes: 92d12f9544b7 ("memblock: refactor internal allocation functions")
> Reported-by: Adam Ford <aford173@gmail.com>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
>  mm/memblock.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 7d4f61a..c4b16ca 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1356,9 +1356,6 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
>                 align = SMP_CACHE_BYTES;
>         }
>
> -       if (end > memblock.current_limit)
> -               end = memblock.current_limit;
> -
>  again:
>         found = memblock_find_in_range_node(size, align, start, end, nid,
>                                             flags);
> @@ -1469,6 +1466,9 @@ static void * __init memblock_alloc_internal(
>         if (WARN_ON_ONCE(slab_is_available()))
>                 return kzalloc_node(size, GFP_NOWAIT, nid);
>
> +       if (max_addr > memblock.current_limit)
> +               max_addr = memblock.current_limit;
> +
>         alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid);
>
>         /* retry allocation without lower limit */
> --
> 2.7.4
>
>
> > > adam
> > >
> > > On Sat, Sep 28, 2019 at 2:33 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
> > > >
> > > > On Thu, Sep 26, 2019 at 02:35:53PM -0500, Adam Ford wrote:
> > > > > On Thu, Sep 26, 2019 at 11:04 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > On Thu, Sep 26, 2019 at 08:09:52AM -0500, Adam Ford wrote:
> > > > > > > On Wed, Sep 25, 2019 at 10:17 AM Fabio Estevam <festevam@gmail.com> wrote:
> > > > > > > >
> > > > > > > > On Wed, Sep 25, 2019 at 9:17 AM Adam Ford <aford173@gmail.com> wrote:
> > > > > > > >
> > > > > > > > > I tried cma=256M and noticed the cma dump at the beginning didn't
> > > > > > > > > change.  Do we need to setup a reserved-memory node like
> > > > > > > > > imx6ul-ccimx6ulsom.dtsi did?
> > > > > > > >
> > > > > > > > I don't think so.
> > > > > > > >
> > > > > > > > Were you able to identify what was the exact commit that caused such regression?
> > > > > > >
> > > > > > > I was able to narrow it down the 92d12f9544b7 ("memblock: refactor
> > > > > > > internal allocation functions") that caused the regression with
> > > > > > > Etnaviv.
> > > > > >
> > > > > >
> > > > > > Can you please test with this change:
> > > > > >
> > > > >
> > > > > That appears to have fixed my issue.  I am not sure what the impact
> > > > > is, but is this a safe option?
> > > >
> > > > It's not really a fix, I just wanted to see how exactly 92d12f9544b7 ("memblock:
> > > > refactor internal allocation functions") broke your setup.
> > > >
> > > > Can you share the dts you are using and the full kernel log?
> > > >
> > > > > adam
> > > > >
> > > > > > diff --git a/mm/memblock.c b/mm/memblock.c
> > > > > > index 7d4f61a..1f5a0eb 100644
> > > > > > --- a/mm/memblock.c
> > > > > > +++ b/mm/memblock.c
> > > > > > @@ -1356,9 +1356,6 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
> > > > > >                 align = SMP_CACHE_BYTES;
> > > > > >         }
> > > > > >
> > > > > > -       if (end > memblock.current_limit)
> > > > > > -               end = memblock.current_limit;
> > > > > > -
> > > > > >  again:
> > > > > >         found = memblock_find_in_range_node(size, align, start, end, nid,
> > > > > >                                             flags);
> > > > > >
> > > > > > > I also noticed that if I create a reserved memory node as was done one
> > > > > > > imx6ul-ccimx6ulsom.dtsi the 3D seems to work again, but without it, I
> > > > > > > was getting errors regardless of the 'cma=256M' or not.
> > > > > > > I don't have a problem using the reserved memory, but I guess I am not
> > > > > > > sure what the amount should be.  I know for the video decoding 1080p,
> > > > > > > I have historically used cma=128M, but with the 3D also needing some
> > > > > > > memory allocation, is that enough or should I use 256M?
> > > > > > >
> > > > > > > adam
> > > > > >
> > > > > > --
> > > > > > Sincerely yours,
> > > > > > Mike.
> > > > > >
> > > >
> > > > --
> > > > Sincerely yours,
> > > > Mike.
> > > >
>
> --
> Sincerely yours,
> Mike.
>