From: Michal Hocko <mhocko@kernel.org>
To: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>,
lkml <linux-kernel@vger.kernel.org>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH] mm/memblock: replace u64 with phys_addr_t where appropriate
Date: Wed, 4 Jul 2018 15:29:05 +0200 [thread overview]
Message-ID: <20180704132905.GS22503@dhcp22.suse.cz> (raw)
In-Reply-To: <20180704132410.GH4352@rapoport-lnx>
On Wed 04-07-18 16:24:11, Mike Rapoport wrote:
> On Wed, Jul 04, 2018 at 03:05:00PM +0200, Michal Hocko wrote:
> > On Tue 03-07-18 20:05:06, Mike Rapoport wrote:
> > > Most functions in memblock already use phys_addr_t to represent a physical
> > > address with __memblock_free_late() being an exception.
> > >
> > > This patch replaces u64 with phys_addr_t in __memblock_free_late() and
> > > switches several format strings from %llx to %pa to avoid casting from
> > > phys_addr_t to u64.
> > >
> > > CC: Michal Hocko <mhocko@kernel.org>
> > > CC: Matthew Wilcox <willy@infradead.org>
> > > Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> > > ---
> > > mm/memblock.c | 46 +++++++++++++++++++++++-----------------------
> > > 1 file changed, 23 insertions(+), 23 deletions(-)
> > >
> > > diff --git a/mm/memblock.c b/mm/memblock.c
> > > index 03d48d8..20ad8e9 100644
> > > --- a/mm/memblock.c
> > > +++ b/mm/memblock.c
> > > @@ -330,7 +330,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type,
> > > {
> > > struct memblock_region *new_array, *old_array;
> > > phys_addr_t old_alloc_size, new_alloc_size;
> > > - phys_addr_t old_size, new_size, addr;
> > > + phys_addr_t old_size, new_size, addr, new_end;
> > > int use_slab = slab_is_available();
> > > int *in_slab;
> > >
> > > @@ -391,9 +391,9 @@ static int __init_memblock memblock_double_array(struct memblock_type *type,
> > > return -1;
> > > }
> > >
> > > - memblock_dbg("memblock: %s is doubled to %ld at [%#010llx-%#010llx]",
> > > - type->name, type->max * 2, (u64)addr,
> > > - (u64)addr + new_size - 1);
> > > + new_end = addr + new_size - 1;
> > > + memblock_dbg("memblock: %s is doubled to %ld at [%pa-%pa]",
> > > + type->name, type->max * 2, &addr, &new_end);
> >
> > I didn't get to check this carefully but this surely looks suspicious. I
> > am pretty sure you wanted to print the value here rather than address of
> > the local variable, right?
>
> It's the semantics of %pa:
>
> Physical address types phys_addr_t
> ----------------------------------
>
> ::
>
> %pa[p] 0x01234567 or 0x0123456789abcdef
>
> For printing a phys_addr_t type (and its derivatives, such as
> resource_size_t) which can vary based on build options, regardless of the
> width of the CPU data path.
>
> Passed by reference.
I wasn't aware of that. Thanks for the clarification!
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-07-04 13:29 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-03 17:05 [PATCH] mm/memblock: replace u64 with phys_addr_t where appropriate Mike Rapoport
2018-07-03 17:22 ` Pavel Tatashin
2018-07-03 19:57 ` Andrew Morton
2018-07-03 20:24 ` Joe Perches
2018-07-04 7:03 ` Mike Rapoport
2018-07-04 7:23 ` Sergey Senozhatsky
2018-07-04 9:04 ` Joe Perches
2018-07-04 9:20 ` Sergey Senozhatsky
2018-07-04 9:43 ` Sergey Senozhatsky
2018-07-04 15:20 ` Mike Rapoport
2018-07-04 7:54 ` Sergey Senozhatsky
2018-07-04 15:21 ` Mike Rapoport
2018-07-04 17:22 ` Joe Perches
2018-07-05 7:12 ` Mike Rapoport
2018-07-04 7:02 ` Mike Rapoport
2018-07-04 13:05 ` Michal Hocko
2018-07-04 13:24 ` Mike Rapoport
2018-07-04 13:29 ` Michal Hocko [this message]
2018-07-04 14:04 ` Michal Hocko
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