From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Heiko Carstens <heiko.carstens@de.ibm.com>,
Pavel Tatashin <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, borntraeger@de.ibm.com,
davem@davemloft.net, willy@infradead.org
Subject: Re: [v2 5/5] mm: teach platforms not to zero struct pages memory
Date: Fri, 07 Apr 2017 11:45:23 +0530 [thread overview]
Message-ID: <87bms8rbes.fsf@skywalker.in.ibm.com> (raw)
In-Reply-To: <20170327060032.GB5092@osiris>
Heiko Carstens <heiko.carstens@de.ibm.com> writes:
> On Fri, Mar 24, 2017 at 03:19:52PM -0400, Pavel Tatashin wrote:
>> If we are using deferred struct page initialization feature, most of
>> "struct page"es are getting initialized after other CPUs are started, and
>> hence we are benefiting from doing this job in parallel. However, we are
>> still zeroing all the memory that is allocated for "struct pages" using the
>> boot CPU. This patch solves this problem, by deferring zeroing "struct
>> pages" to only when they are initialized.
>>
>> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
>> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
>> ---
>> arch/powerpc/mm/init_64.c | 2 +-
>> arch/s390/mm/vmem.c | 2 +-
>> arch/sparc/mm/init_64.c | 2 +-
>> arch/x86/mm/init_64.c | 2 +-
>> 4 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
>> index eb4c270..24faf2d 100644
>> --- a/arch/powerpc/mm/init_64.c
>> +++ b/arch/powerpc/mm/init_64.c
>> @@ -181,7 +181,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
>> if (vmemmap_populated(start, page_size))
>> continue;
>>
>> - p = vmemmap_alloc_block(page_size, node, true);
>> + p = vmemmap_alloc_block(page_size, node, VMEMMAP_ZERO);
>> if (!p)
>> return -ENOMEM;
>>
>> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
>> index 9c75214..ffe9ba1 100644
>> --- a/arch/s390/mm/vmem.c
>> +++ b/arch/s390/mm/vmem.c
>> @@ -252,7 +252,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
>> void *new_page;
>>
>> new_page = vmemmap_alloc_block(PMD_SIZE, node,
>> - true);
>> + VMEMMAP_ZERO);
>> if (!new_page)
>> goto out;
>> pmd_val(*pm_dir) = __pa(new_page) | sgt_prot;
>
> s390 has two call sites that need to be converted, like you did in one of
> your previous patches. The same seems to be true for powerpc, unless there
> is a reason to not convert them?
>
vmemmap_list_alloc is not really struct page allocation right ? We are
just allocating memory to be used as vmemmmap_backing. But considering
we are updating all the three elements of the sturct, we can avoid that
memset . But instead of VMEMMAP_ZERO we can just pass false in that case
?
-aneesh
next prev parent reply other threads:[~2017-04-07 6:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-24 19:19 [v2 0/5] parallelized "struct page" zeroing Pavel Tatashin
2017-03-24 19:19 ` [v2 1/5] sparc64: simplify vmemmap_populate Pavel Tatashin
2017-03-24 19:19 ` [v2 2/5] mm: defining memblock_virt_alloc_try_nid_raw Pavel Tatashin
2017-03-24 19:19 ` [v2 3/5] mm: add "zero" argument to vmemmap allocators Pavel Tatashin
2017-05-03 14:34 ` David Miller
2017-05-03 15:05 ` Pasha Tatashin
2017-03-24 19:19 ` [v2 4/5] mm: zero struct pages during initialization Pavel Tatashin
2017-03-24 19:19 ` [v2 5/5] mm: teach platforms not to zero struct pages memory Pavel Tatashin
2017-03-27 6:00 ` Heiko Carstens
2017-04-07 6:15 ` Aneesh Kumar K.V [this message]
2017-03-25 21:25 ` [v2 0/5] parallelized "struct page" zeroing Matthew Wilcox
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=87bms8rbes.fsf@skywalker.in.ibm.com \
--to=aneesh.kumar@linux.vnet.ibm.com \
--cc=borntraeger@de.ibm.com \
--cc=davem@davemloft.net \
--cc=heiko.carstens@de.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-s390@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=pasha.tatashin@oracle.com \
--cc=sparclinux@vger.kernel.org \
--cc=willy@infradead.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).