From: Baoquan He <bhe@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@suse.com,
david@redhat.com, richard.weiyang@gmail.com,
dan.j.williams@intel.com, bhe@redhat.com
Subject: [PATCH v4 2/5] mm/sparse.c: introduce a new function clear_subsection_map()
Date: Thu, 12 Mar 2020 20:44:11 +0800 [thread overview]
Message-ID: <20200312124414.439-3-bhe@redhat.com> (raw)
In-Reply-To: <20200312124414.439-1-bhe@redhat.com>
Factor out the code which clear subsection map of one memory region from
section_deactivate() into clear_subsection_map().
And also add helper function is_subsection_map_empty() to check if
the current subsection map is empty or not.
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
mm/sparse.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 5919bc5b1547..0be4d4ed96de 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -726,15 +726,11 @@ static void free_map_bootmem(struct page *memmap)
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
-static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
- struct vmem_altmap *altmap)
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
{
DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
struct mem_section *ms = __pfn_to_section(pfn);
- bool section_is_early = early_section(ms);
- struct page *memmap = NULL;
- bool empty;
unsigned long *subsection_map = ms->usage
? &ms->usage->subsection_map[0] : NULL;
@@ -745,8 +741,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
"section already deactivated (%#lx + %ld)\n",
pfn, nr_pages))
- return;
+ return -EINVAL;
+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
+ return 0;
+}
+
+static bool is_subsection_map_empty(struct mem_section *ms)
+{
+ return bitmap_empty(&ms->usage->subsection_map[0],
+ SUBSECTIONS_PER_SECTION);
+}
+
+static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
+ struct vmem_altmap *altmap)
+{
+ struct mem_section *ms = __pfn_to_section(pfn);
+ bool section_is_early = early_section(ms);
+ struct page *memmap = NULL;
+ bool empty;
+
+ if (clear_subsection_map(pfn, nr_pages))
+ return;
/*
* There are 3 cases to handle across two configurations
* (SPARSEMEM_VMEMMAP={y,n}):
@@ -764,8 +780,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
*
* For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
*/
- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
- empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION);
+ empty = is_subsection_map_empty(ms);
if (empty) {
unsigned long section_nr = pfn_to_section_nr(pfn);
--
2.17.2
next prev parent reply other threads:[~2020-03-12 12:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 12:44 [PATCH v4 0/5] mm/hotplug: Only use subsection map for VMEMMAP Baoquan He
2020-03-12 12:44 ` [PATCH v4 1/5] mm/sparse.c: introduce new function fill_subsection_map() Baoquan He
2020-03-12 13:30 ` Pankaj Gupta
2020-03-12 12:44 ` Baoquan He [this message]
2020-03-12 13:26 ` [PATCH v4 2/5] mm/sparse.c: introduce a new function clear_subsection_map() Pankaj Gupta
2020-03-12 12:44 ` [PATCH v4 3/5] mm/sparse.c: only use subsection map in VMEMMAP case Baoquan He
2020-03-12 12:44 ` [PATCH v4 4/5] mm/sparse.c: add note about only VMEMMAP supporting sub-section hotplug Baoquan He
2020-03-12 13:45 ` David Hildenbrand
2020-03-12 12:44 ` [PATCH v4 5/5] mm/sparse.c: move subsection_map related functions together Baoquan He
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=20200312124414.439-3-bhe@redhat.com \
--to=bhe@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=richard.weiyang@gmail.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).