From: David Laight <David.Laight@ACULAB.COM>
To: 'Michal Hocko' <mhocko@kernel.org>
Cc: 'Pavel Tatashin' <pasha.tatashin@oracle.com>,
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Subject: RE: [PATCH v10 09/10] mm: stop zeroing memory during allocation in vmemmap
Date: Fri, 6 Oct 2017 12:11:42 +0000 [thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6DD008BB4D@AcuExch.aculab.com> (raw)
In-Reply-To: <20171006114729.fexwklupkhyxdpt3@dhcp22.suse.cz>
From: Michal Hocko
> Sent: 06 October 2017 12:47
> On Fri 06-10-17 11:10:14, David Laight wrote:
> > From: Pavel Tatashin
> > > Sent: 05 October 2017 22:11
> > > vmemmap_alloc_block() will no longer zero the block, so zero memory
> > > at its call sites for everything except struct pages. Struct page memory
> > > is zero'd by struct page initialization.
> >
> > It seems dangerous to change an allocator to stop zeroing memory.
> > It is probably saver to add a new function that doesn't zero
> > the memory and use that is the places where you don't want it
> > to be zeroed.
>
> Not sure what you mean. memblock_virt_alloc_try_nid_raw is a new
> function which doesn't zero out...
You should probably leave vmemap_alloc_block() zeroing the memory
so that existing alls don't have to be changed - apart from the
ones you are explicitly optimising.
David
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next prev parent reply other threads:[~2017-10-06 12:11 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-05 21:11 [PATCH v10 00/10] complete deferred page initialization Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 01/10] x86/mm: setting fields in deferred pages Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 02/10] sparc64/mm: " Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 03/10] sparc64: simplify vmemmap_populate Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 04/10] mm: defining memblock_virt_alloc_try_nid_raw Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 05/10] mm: zero reserved and unavailable struct pages Pavel Tatashin
2017-10-06 12:30 ` Michal Hocko
2017-10-06 15:25 ` Pasha Tatashin
2017-10-10 13:39 ` Michal Hocko
2017-10-05 21:11 ` [PATCH v10 06/10] mm/kasan: kasan specific map populate function Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 07/10] x86/kasan: use kasan_map_populate() Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 08/10] arm64/kasan: " Pavel Tatashin
2017-10-05 21:11 ` [PATCH v10 09/10] mm: stop zeroing memory during allocation in vmemmap Pavel Tatashin
2017-10-06 11:10 ` David Laight
2017-10-06 11:47 ` Michal Hocko
2017-10-06 12:11 ` David Laight [this message]
2017-10-06 12:25 ` Michal Hocko
2017-10-05 21:11 ` [PATCH v10 10/10] sparc64: optimized struct page zeroing Pavel Tatashin
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