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Re: [PATCH 8/9] bcache: use kvmalloc

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On Mon 30-01-17 17:47:31, Vlastimil Babka wrote:
> On 01/30/2017 10:49 AM, Michal Hocko wrote:
> > From: Michal Hocko <mhocko@suse.com>
> > 
> > bcache_device_init uses kmalloc for small requests and vmalloc for those
> > which are larger than 64 pages. This alone is a strange criterion.
> > Moreover kmalloc can fallback to vmalloc on the failure. Let's simply
> > use kvmalloc instead as it knows how to handle the fallback properly
> 
> I don't see why separate patch, some of the conversions in 5/9 were quite
> similar (except comparing with PAGE_SIZE, not 64*PAGE_SIZE), but nevermind.

I just found it later so I kept it separate. It can be folded to 5/9 if
that makes more sense.
 
> > Cc: Kent Overstreet <kent.overstreet@gmail.com>
> > Signed-off-by: Michal Hocko <mhocko@suse.com>
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>

Thanks!

> > ---
> >  drivers/md/bcache/super.c | 8 ++------
> >  1 file changed, 2 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> > index 3a19cbc8b230..4cb6b88a1465 100644
> > --- a/drivers/md/bcache/super.c
> > +++ b/drivers/md/bcache/super.c
> > @@ -767,16 +767,12 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
> >  	}
> > 
> >  	n = d->nr_stripes * sizeof(atomic_t);
> > -	d->stripe_sectors_dirty = n < PAGE_SIZE << 6
> > -		? kzalloc(n, GFP_KERNEL)
> > -		: vzalloc(n);
> > +	d->stripe_sectors_dirty = kvzalloc(n, GFP_KERNEL);
> >  	if (!d->stripe_sectors_dirty)
> >  		return -ENOMEM;
> > 
> >  	n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long);
> > -	d->full_dirty_stripes = n < PAGE_SIZE << 6
> > -		? kzalloc(n, GFP_KERNEL)
> > -		: vzalloc(n);
> > +	d->full_dirty_stripes = kvzalloc(n, GFP_KERNEL);
> >  	if (!d->full_dirty_stripes)
> >  		return -ENOMEM;
> > 
> > 

-- 
Michal Hocko
SUSE Labs

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[PATCH 0/6 v3] kvmalloc Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
  [PATCH 8/9] bcache: use kvmalloc Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
    Re: [PATCH 8/9] bcache: use kvmalloc Vlastimil Babka <vbabka@suse.cz> - 2017-01-30 18:00 +0100
      Re: [PATCH 8/9] bcache: use kvmalloc Michal Hocko <mhocko@kernel.org> - 2017-01-30 18:30 +0100
  [PATCH 9/9] net, bpf: use kvzalloc helper Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
    Re: [PATCH 9/9] net, bpf: use kvzalloc helper Michal Hocko <mhocko@kernel.org> - 2017-01-30 18:30 +0100
  [PATCH 4/9] ila: simplify a strange allocation pattern Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
    Re: [PATCH 4/9] ila: simplify a strange allocation pattern Vlastimil Babka <vbabka@suse.cz> - 2017-01-30 16:30 +0100
  [PATCH 2/9] mm: support __GFP_REPEAT in kvmalloc_node for >32kB Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
  [PATCH 7/9] md: use kvmalloc rather than opencoded variant Michal Hocko <mhocko@kernel.org> - 2017-01-30 11:00 +0100
    Re: [PATCH 7/9] md: use kvmalloc rather than opencoded variant Vlastimil Babka <vbabka@suse.cz> - 2017-01-30 18:00 +0100
    Re: [PATCH 7/9] md: use kvmalloc rather than opencoded variant Mikulas Patocka <mpatocka@redhat.com> - 2017-02-01 18:40 +0100
      Re: [PATCH 7/9] md: use kvmalloc rather than opencoded variant Michal Hocko <mhocko@kernel.org> - 2017-02-01 19:00 +0100
  Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded  variants Leon Romanovsky <leon@kernel.org> - 2017-01-30 11:40 +0100
  Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded  variants Vlastimil Babka <vbabka@suse.cz> - 2017-01-30 17:40 +0100
  Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded variants Kees Cook <keescook@chromium.org> - 2017-01-30 20:30 +0100
  Re: [PATCH 0/6 v3] kvmalloc Michal Hocko <mhocko@kernel.org> - 2017-02-05 11:30 +0100

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