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Date: Thu, 4 Apr 2013 10:17:02 +0200
From: Michal Hocko <mhocko@...e.cz>
To: Robin Holt <holt@....com>
Cc: Cliff Wickman <cpw@....com>, linux-kernel@...r.kernel.org,
linux-mm@...ck.org, x86@...nel.org, wli@...omorphy.com
Subject: Re: [PATCH] mm, x86: Do not zero hugetlbfs pages at boot. -v2
On Wed 03-04-13 12:21:32, Robin Holt wrote:
> On Wed, Apr 03, 2013 at 04:00:49PM +0200, Michal Hocko wrote:
> > On Tue 02-04-13 21:43:44, Robin Holt wrote:
> > [...]
> > > diff --git a/mm/bootmem.c b/mm/bootmem.c
> > > index 2b0bcb0..b2e4027 100644
> > > --- a/mm/bootmem.c
> > > +++ b/mm/bootmem.c
> > > @@ -705,12 +705,16 @@ void * __init __alloc_bootmem(unsigned long size, unsigned long align,
> > >
> > > void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
> > > unsigned long size, unsigned long align,
> > > - unsigned long goal, unsigned long limit)
> > > + unsigned long goal, unsigned long limit,
> > > + int zeroed)
> > > {
> > > void *ptr;
> > >
> > > if (WARN_ON_ONCE(slab_is_available()))
> > > - return kzalloc(size, GFP_NOWAIT);
> > > + if (zeroed)
> > > + return kzalloc(size, GFP_NOWAIT);
> > > + else
> > > + return kmalloc(size, GFP_NOWAIT);
> > > again:
> > >
> > > /* do not panic in alloc_bootmem_bdata() */
> >
> > You need to update alloc_bootmem_bdata and alloc_bootmem_core as well.
> > Otherwise this is a no-op for early allocations when slab is not
> > available which is the case unless something is broken.
>
> Michal,
>
> Does this do what you would expect?
yes, it looks right when I quickly glanced over it. I haven't checked
deeply yet. I would suggest reposting and adding more *bootmem people
into CC (e.g. Johannes Weiner, Yinghai Lu, Tejun Heo and maybe others).
> I compiled this for ia64, but I have not tested it at all.
>
> Robin
>
> ---
> mm/bootmem.c | 30 +++++++++++++++++++-----------
> 1 file changed, 19 insertions(+), 11 deletions(-)
>
> diff --git a/mm/bootmem.c b/mm/bootmem.c
> index b2e4027..350e0ab 100644
> --- a/mm/bootmem.c
> +++ b/mm/bootmem.c
> @@ -497,7 +497,8 @@ static unsigned long __init align_off(struct bootmem_data *bdata,
>
> static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata,
> unsigned long size, unsigned long align,
> - unsigned long goal, unsigned long limit)
> + unsigned long goal, unsigned long limit,
> + int zeroed)
> {
> unsigned long fallback = 0;
> unsigned long min, max, start, sidx, midx, step;
> @@ -584,7 +585,8 @@ find_block:
>
> region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
> start_off);
> - memset(region, 0, size);
> + if (zeroed)
> + memset(region, 0, size);
> /*
> * The min_count is set to 0 so that bootmem allocated blocks
> * are never reported as leaks.
> @@ -605,13 +607,18 @@ find_block:
> static void * __init alloc_bootmem_core(unsigned long size,
> unsigned long align,
> unsigned long goal,
> - unsigned long limit)
> + unsigned long limit,
> + int zeroed)
> {
> bootmem_data_t *bdata;
> void *region;
>
> - if (WARN_ON_ONCE(slab_is_available()))
> - return kzalloc(size, GFP_NOWAIT);
> + if (WARN_ON_ONCE(slab_is_available())) {
> + if (zeroed)
> + return kzalloc(size, GFP_NOWAIT);
> + else
> + return kmalloc(size, GFP_NOWAIT);
> + }
>
> list_for_each_entry(bdata, &bdata_list, list) {
> if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
> @@ -619,7 +626,7 @@ static void * __init alloc_bootmem_core(unsigned long size,
> if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
> break;
>
> - region = alloc_bootmem_bdata(bdata, size, align, goal, limit);
> + region = alloc_bootmem_bdata(bdata, size, align, goal, limit, zeroed);
> if (region)
> return region;
> }
> @@ -635,7 +642,7 @@ static void * __init ___alloc_bootmem_nopanic(unsigned long size,
> void *ptr;
>
> restart:
> - ptr = alloc_bootmem_core(size, align, goal, limit);
> + ptr = alloc_bootmem_core(size, align, goal, limit, 1);
> if (ptr)
> return ptr;
> if (goal) {
> @@ -710,22 +717,23 @@ void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
> {
> void *ptr;
>
> - if (WARN_ON_ONCE(slab_is_available()))
> + if (WARN_ON_ONCE(slab_is_available())) {
> if (zeroed)
> return kzalloc(size, GFP_NOWAIT);
> else
> return kmalloc(size, GFP_NOWAIT);
> + }
> again:
>
> /* do not panic in alloc_bootmem_bdata() */
> if (limit && goal + size > limit)
> limit = 0;
>
> - ptr = alloc_bootmem_bdata(pgdat->bdata, size, align, goal, limit);
> + ptr = alloc_bootmem_bdata(pgdat->bdata, size, align, goal, limit, zeroed);
> if (ptr)
> return ptr;
>
> - ptr = alloc_bootmem_core(size, align, goal, limit);
> + ptr = alloc_bootmem_core(size, align, goal, limit, zeroed);
> if (ptr)
> return ptr;
>
> @@ -813,7 +821,7 @@ void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
>
> new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
> ptr = alloc_bootmem_bdata(pgdat->bdata, size, align,
> - new_goal, 0);
> + new_goal, 0, 1);
> if (ptr)
> return ptr;
> }
> --
> 1.8.1.2
>
> --
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--
Michal Hocko
SUSE Labs
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