Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 3 Aug 2021 10:58:42 +0300
From:   Mike Rapoport <rppt@kernel.org>
To:     Joe Perches <joe@perches.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Michal Simek <monstr@monstr.eu>,
        Mike Rapoport <rppt@linux.ibm.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 4/4] memblock: stop poisoning raw allocations
Message-ID: <YQj3MqOON6qySFFa@kernel.org>
References: <20210714123739.16493-1-rppt@kernel.org>
 <20210714123739.16493-5-rppt@kernel.org>
 <72be13936ca341897d2fd7c65fb4345a8467c571.camel@perches.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <72be13936ca341897d2fd7c65fb4345a8467c571.camel@perches.com>
Precedence: bulk

On Sat, Jul 31, 2021 at 10:13:04AM -0700, Joe Perches wrote:
> On Wed, 2021-07-14 at 15:37 +0300, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> > 
> > Functions memblock_alloc_exact_nid_raw() and memblock_alloc_try_nid_raw()
> > are intended for early memory allocation without overhead of zeroing the
> > allocated memory. Since these functions were used to allocate the memory
> > map, they have ended up with addition of a call to page_init_poison() that
> > poisoned the allocated memory when CONFIG_PAGE_POISON was set.
> > 
> > Since the memory map is allocated using a dedicated memmep_alloc() function
> > that takes care of the poisoning, remove page poisoning from the
> > memblock_alloc_*_raw() functions.
> []
> > diff --git a/mm/memblock.c b/mm/memblock.c
> []
> > @@ -1490,18 +1490,12 @@ void * __init memblock_alloc_exact_nid_raw(
> > ?			phys_addr_t min_addr, phys_addr_t max_addr,
> > ?			int nid)
> > ?{
> > -	void *ptr;
> > -
> > ?	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
> > ?		     __func__, (u64)size, (u64)align, nid, &min_addr,
> > ?		     &max_addr, (void *)_RET_IP_);
> 
> unassociated trivia:
> 
> casting _RET_IP_ back to void * seems odd as the define is
> include/linux/kernel.h:#define _RET_IP_         (unsigned long)__builtin_return_address(0)
> 
> It's probably easier to understand as just __builtin_return_address(0)

Maybe, but I'm not sure it's worth the churn.
 
> > @@ -1528,18 +1522,12 @@ void * __init memblock_alloc_try_nid_raw(
> > ?			phys_addr_t min_addr, phys_addr_t max_addr,
> > ?			int nid)
> > ?{
> > -	void *ptr;
> > -
> > ?	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
> > ?		     __func__, (u64)size, (u64)align, nid, &min_addr,
> > ?		     &max_addr, (void *)_RET_IP_);
> 
> here too
> 

-- 
Sincerely yours,
Mike.