From: David Miller <davem@davemloft.net>
To: pasha.tatashin@oracle.com
Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,
linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
x86@kernel.org, kasan-dev@googlegroups.com,
borntraeger@de.ibm.com, heiko.carstens@de.ibm.com,
willy@infradead.org, mhocko@kernel.org,
ard.biesheuvel@linaro.org, will.deacon@arm.com,
catalin.marinas@arm.com, sam@ravnborg.org,
mgorman@techsingularity.net, Steven.Sistare@oracle.com,
daniel.m.jordan@oracle.com, bob.picco@oracle.com
Subject: Re: [PATCH v7 02/11] sparc64/mm: setting fields in deferred pages
Date: Tue, 29 Aug 2017 18:09:28 -0700 (PDT) [thread overview]
Message-ID: <20170829.180928.896986367806428362.davem@davemloft.net> (raw)
In-Reply-To: <1503972142-289376-3-git-send-email-pasha.tatashin@oracle.com>
From: Pavel Tatashin <pasha.tatashin@oracle.com>
Date: Mon, 28 Aug 2017 22:02:13 -0400
> Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
> flags and other fields in "struct page"es are never changed prior to first
> initializing struct pages by going through __init_single_page().
>
> With deferred struct page feature enabled there is a case where we set some
> fields prior to initializing:
>
> mem_init() {
> register_page_bootmem_info();
> free_all_bootmem();
> ...
> }
>
> When register_page_bootmem_info() is called only non-deferred struct pages
> are initialized. But, this function goes through some reserved pages which
> might be part of the deferred, and thus are not yet initialized.
>
> mem_init
> register_page_bootmem_info
> register_page_bootmem_info_node
> get_page_bootmem
> .. setting fields here ..
> such as: page->freelist = (void *)type;
>
> free_all_bootmem()
> free_low_memory_core_early()
> for_each_reserved_mem_region()
> reserve_bootmem_region()
> init_reserved_page() <- Only if this is deferred reserved page
> __init_single_pfn()
> __init_single_page()
> memset(0) <-- Loose the set fields here
>
> We end-up with similar issue as in the previous patch, where currently we
> do not observe problem as memory is zeroed. But, if flag asserts are
> changed we can start hitting issues.
>
> Also, because in this patch series we will stop zeroing struct page memory
> during allocation, we must make sure that struct pages are properly
> initialized prior to using them.
>
> The deferred-reserved pages are initialized in free_all_bootmem().
> Therefore, the fix is to switch the above calls.
>
> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
> Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
> Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
next prev parent reply other threads:[~2017-08-30 1:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-29 2:02 [PATCH v7 00/11] complete deferred page initialization Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 01/11] x86/mm: setting fields in deferred pages Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 02/11] sparc64/mm: " Pavel Tatashin
2017-08-30 1:09 ` David Miller [this message]
2017-08-29 2:02 ` [PATCH v7 03/11] mm: deferred_init_memmap improvements Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 04/11] sparc64: simplify vmemmap_populate Pavel Tatashin
2017-08-30 1:08 ` David Miller
2017-08-29 2:02 ` [PATCH v7 05/11] mm: defining memblock_virt_alloc_try_nid_raw Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 06/11] mm: zero struct pages during initialization Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 07/11] sparc64: optimized struct page zeroing Pavel Tatashin
2017-08-30 1:12 ` David Miller
2017-08-30 13:19 ` Pasha Tatashin
2017-08-30 17:46 ` David Miller
2017-08-29 2:02 ` [PATCH v7 08/11] mm: zero reserved and unavailable struct pages Pavel Tatashin
2017-08-30 21:22 ` kbuild test robot
2017-08-30 23:12 ` kbuild test robot
2017-08-29 2:02 ` [PATCH v7 09/11] x86/kasan: explicitly zero kasan shadow memory Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 10/11] arm64/kasan: " Pavel Tatashin
2017-08-29 2:02 ` [PATCH v7 11/11] mm: stop zeroing memory during allocation in vmemmap Pavel Tatashin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170829.180928.896986367806428362.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=Steven.Sistare@oracle.com \
--cc=ard.biesheuvel@linaro.org \
--cc=bob.picco@oracle.com \
--cc=borntraeger@de.ibm.com \
--cc=catalin.marinas@arm.com \
--cc=daniel.m.jordan@oracle.com \
--cc=heiko.carstens@de.ibm.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-s390@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@kernel.org \
--cc=pasha.tatashin@oracle.com \
--cc=sam@ravnborg.org \
--cc=sparclinux@vger.kernel.org \
--cc=will.deacon@arm.com \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).