[PATCH] drm/etnaviv: switch devcoredump allocations to GFP_NOWAIT

[Philipp Zabel]

On Do, 2024-05-16 at 19:20 +0200, Lucas Stach wrote:
> Am Freitag, dem 26.01.2024 um 17:46 +0100 schrieb Lucas Stach:
> > The etnaviv devcoredump is created in the GPU reset path, which
> > must make forward progress to avoid stalling memory reclaim on
> > unsignalled dma fences. The currently used __GFP_NORETRY does not
> > prohibit sleeping on direct reclaim, breaking the forward progress
> > guarantee. Switch to GFP_NOWAIT, which allows background reclaim
> > to be triggered, but avoids any stalls waiting for direct reclaim.
> > 
> Any takers for reviewing this one?
> 
> Regards,
> Lucas
> 
> > Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> > ---
> >  drivers/gpu/drm/etnaviv/etnaviv_dump.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_dump.c b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
> > index 898f84a0fc30c..42c5028872d54 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_dump.c
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
> > @@ -159,8 +159,7 @@ void etnaviv_core_dump(struct etnaviv_gem_submit *submit)
> >  	file_size += sizeof(*iter.hdr) * n_obj;
> >  
> >  	/* Allocate the file in vmalloc memory, it's likely to be big */
> > -	iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN |
> > -			__GFP_NORETRY);
> > +	iter.start = __vmalloc(file_size, GFP_NOWAIT | __GFP_NOWARN);
> >  	if (!iter.start) {
> >  		mutex_unlock(&submit->mmu_context->lock);
> >  		dev_warn(gpu->dev, "failed to allocate devcoredump file\n");
> > @@ -230,5 +229,6 @@ void etnaviv_core_dump(struct etnaviv_gem_submit *submit)
> >  
> >  	etnaviv_core_dump_header(&iter, ETDUMP_BUF_END, iter.data);
> >  
> > -	dev_coredumpv(gpu->dev, iter.start, iter.data - iter.start, GFP_KERNEL);
> > +	dev_coredumpv(gpu->dev, iter.start, iter.data - iter.start,
> > +		      GFP_NOWAIT | __GFP_NOWARN);

Should this be __GFP_NOWARN? There is no fallback on failure, and if
this fails and the __vmalloc() above didn't, there is no error message
at all.

regards
Philipp