From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org, vbabka@suse.cz,
torvalds@linux-foundation.org, rppt@kernel.org,
rostedt@goodmis.org, osalvador@suse.de,
mgorman@techsingularity.net, david@redhat.com, ziy@nvidia.com,
akpm@linux-foundation.org
Subject: + mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch added to -mm tree
Date: Mon, 04 Apr 2022 14:50:45 -0700 [thread overview]
Message-ID: <20220404215046.0B0ADC2BBE4@smtp.kernel.org> (raw)
The patch titled
Subject: mm: page_alloc: simplify pageblock migratetype check in __free_one_page()
has been added to the -mm tree. Its filename is
mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: mm: page_alloc: simplify pageblock migratetype check in __free_one_page()
Move pageblock migratetype check code in the while loop to simplify the
logic. It also saves redundant buddy page checking code.
Link: https://lkml.kernel.org/r/20220401230804.1658207-1-zi.yan@sent.com
Link: https://lore.kernel.org/linux-mm/27ff69f9-60c5-9e59-feb2-295250077551@suse.cz/
Signed-off-by: Zi Yan <ziy@nvidia.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_alloc.c | 46 +++++++++++++++++-----------------------------
1 file changed, 17 insertions(+), 29 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page
+++ a/mm/page_alloc.c
@@ -1054,7 +1054,6 @@ static inline void __free_one_page(struc
int migratetype, fpi_t fpi_flags)
{
struct capture_control *capc = task_capc(zone);
- unsigned int max_order = pageblock_order;
unsigned long buddy_pfn;
unsigned long combined_pfn;
struct page *buddy;
@@ -1070,8 +1069,7 @@ static inline void __free_one_page(struc
VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
VM_BUG_ON_PAGE(bad_range(zone, page), page);
-continue_merging:
- while (order < max_order) {
+ while (order < MAX_ORDER - 1) {
if (compaction_capture(capc, page, order, migratetype)) {
__mod_zone_freepage_state(zone, -(1 << order),
migratetype);
@@ -1082,6 +1080,22 @@ continue_merging:
if (!page_is_buddy(page, buddy, order))
goto done_merging;
+
+ if (unlikely(order >= pageblock_order)) {
+ /*
+ * We want to prevent merge between freepages on pageblock
+ * without fallbacks and normal pageblock. Without this,
+ * pageblock isolation could cause incorrect freepage or CMA
+ * accounting or HIGHATOMIC accounting.
+ */
+ int buddy_mt = get_pageblock_migratetype(buddy);
+
+ if (migratetype != buddy_mt
+ && (!migratetype_is_mergeable(migratetype) ||
+ !migratetype_is_mergeable(buddy_mt)))
+ goto done_merging;
+ }
+
/*
* Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
* merge with it and move up one order.
@@ -1095,32 +1109,6 @@ continue_merging:
pfn = combined_pfn;
order++;
}
- if (order < MAX_ORDER - 1) {
- /* If we are here, it means order is >= pageblock_order.
- * We want to prevent merge between freepages on pageblock
- * without fallbacks and normal pageblock. Without this,
- * pageblock isolation could cause incorrect freepage or CMA
- * accounting or HIGHATOMIC accounting.
- *
- * We don't want to hit this code for the more frequent
- * low-order merging.
- */
- int buddy_mt;
-
- buddy_pfn = __find_buddy_pfn(pfn, order);
- buddy = page + (buddy_pfn - pfn);
-
- if (!page_is_buddy(page, buddy, order))
- goto done_merging;
- buddy_mt = get_pageblock_migratetype(buddy);
-
- if (migratetype != buddy_mt
- && (!migratetype_is_mergeable(migratetype) ||
- !migratetype_is_mergeable(buddy_mt)))
- goto done_merging;
- max_order = order + 1;
- goto continue_merging;
- }
done_merging:
set_buddy_order(page, order);
_
Patches currently in -mm which might be from ziy@nvidia.com are
mm-migrate-use-thp_order-instead-of-hpage_pmd_order-for-new-page-allocation.patch
mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch
mm-wrap-__find_buddy_pfn-with-a-necessary-buddy-page-validation.patch
next reply other threads:[~2022-04-04 22:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-04 21:50 Andrew Morton [this message]
2022-04-07 10:14 ` + mm-page_alloc-simplify-pageblock-migratetype-check-in-__free_one_page.patch added to -mm tree David Hildenbrand
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=20220404215046.0B0ADC2BBE4@smtp.kernel.org \
--to=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mm-commits@vger.kernel.org \
--cc=osalvador@suse.de \
--cc=rostedt@goodmis.org \
--cc=rppt@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=vbabka@suse.cz \
--cc=ziy@nvidia.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.