From: Cannon Matthews <cannonmatthews@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadia Yvette Chambers <nyc@holomorphy.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
andreslc@google.com, pfeiner@google.com, dmatlack@google.com,
gthelen@google.com, Cannon Matthews <cannonmatthews@google.com>
Subject: [PATCH] mm: hugetlb: don't zero 1GiB bootmem pages.
Date: Tue, 10 Jul 2018 11:49:03 -0700 [thread overview]
Message-ID: <20180710184903.68239-1-cannonmatthews@google.com> (raw)
When using 1GiB pages during early boot, use the new
memblock_virt_alloc_try_nid_raw() function to allocate memory without
zeroing it. Zeroing out hundreds or thousands of GiB in a single core
memset() call is very slow, and can make early boot last upwards of
20-30 minutes on multi TiB machines.
To be safe, still zero the first sizeof(struct boomem_huge_page) bytes
since this is used a temporary storage place for this info until
gather_bootmem_prealloc() processes them later.
The rest of the memory does not need to be zero'd as the hugetlb pages
are always zero'd on page fault.
Tested: Booted with ~3800 1G pages, and it booted successfully in
roughly the same amount of time as with 0, as opposed to the 25+
minutes it would take before.
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
---
mm/hugetlb.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3612fbb32e9d..c93a2c77e881 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2101,7 +2101,7 @@ int __alloc_bootmem_huge_page(struct hstate *h)
for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
void *addr;
- addr = memblock_virt_alloc_try_nid_nopanic(
+ addr = memblock_virt_alloc_try_nid_raw(
huge_page_size(h), huge_page_size(h),
0, BOOTMEM_ALLOC_ACCESSIBLE, node);
if (addr) {
@@ -2109,7 +2109,12 @@ int __alloc_bootmem_huge_page(struct hstate *h)
* Use the beginning of the huge page to store the
* huge_bootmem_page struct (until gather_bootmem
* puts them into the mem_map).
+ *
+ * memblock_virt_alloc_try_nid_raw returns non-zero'd
+ * memory so zero out just enough for this struct, the
+ * rest will be zero'd on page fault.
*/
+ memset(addr, 0, sizeof(struct huge_bootmem_page));
m = addr;
goto found;
}
--
2.18.0.203.gfac676dfb9-goog
next reply other threads:[~2018-07-10 18:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-10 18:49 Cannon Matthews [this message]
2018-07-10 20:46 ` [PATCH] mm: hugetlb: don't zero 1GiB bootmem pages Mike Kravetz
2018-07-11 12:49 ` Michal Hocko
2018-07-11 12:47 ` Michal Hocko
2018-07-11 12:48 ` Michal Hocko
2018-07-11 16:47 ` Mike Kravetz
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=20180710184903.68239-1-cannonmatthews@google.com \
--to=cannonmatthews@google.com \
--cc=akpm@linux-foundation.org \
--cc=andreslc@google.com \
--cc=dmatlack@google.com \
--cc=gthelen@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=nyc@holomorphy.com \
--cc=pfeiner@google.com \
/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).