From: lantianyu1986@gmail.com
To: kys@microsoft.com, haiyangz@microsoft.com,
sthemmin@microsoft.com, sashal@kernel.org,
michael.h.kelley@microsoft.com, david@redhat.com
Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
vkuznets@redhat.com, eric.devolder@oracle.com
Subject: [RFC PATCH V2 9/10] x86/Hyper-V/Balloon: Hot add mem in the gaps of hot add region
Date: Tue, 7 Jan 2020 21:09:49 +0800 [thread overview]
Message-ID: <20200107130950.2983-10-Tianyu.Lan@microsoft.com> (raw)
In-Reply-To: <20200107130950.2983-1-Tianyu.Lan@microsoft.com>
From: Tianyu Lan <Tianyu.Lan@microsoft.com>
Mem hot remove operation may find memory in the hot add region
and create gaps in ha region list if there is hot-add memory
at that point. The following hot add msg may contain memory range
in these gaps. Handle such request and change gap range after
adding memory.
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
drivers/hv/hv_balloon.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 105 insertions(+), 3 deletions(-)
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index f76c9bd7fe2f..5aaae62955bf 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -907,10 +907,11 @@ static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
continue;
/*
- * If the current start pfn is not where the covered_end
- * is, create a gap and update covered_end_pfn.
+ * If the current start pfn is greater than covered_end_pfn,
+ * create a gap and update covered_end_pfn. Start pfn may
+ * locate at gap rangs which is created during mem hot remove.
*/
- if (has->covered_end_pfn != start_pfn) {
+ if (has->covered_end_pfn < start_pfn) {
gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC);
if (!gap) {
ret = -ENOMEM;
@@ -949,6 +950,91 @@ static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
return ret;
}
+static int handle_hot_add_in_gap(unsigned long start, unsigned long pg_cnt,
+ struct hv_hotadd_state *has)
+{
+ struct hv_hotadd_gap *gap, *new_gap, *tmp_gap;
+ unsigned long pfn_cnt = pg_cnt;
+ unsigned long start_pfn = start;
+ unsigned long end_pfn;
+ unsigned long pages;
+ unsigned long pgs_ol;
+ unsigned long block_pages = HA_CHUNK;
+ unsigned long pfn;
+ int nid;
+ int ret;
+
+ list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
+
+ if ((start_pfn < gap->start_pfn)
+ || (start_pfn >= gap->end_pfn))
+ continue;
+
+ end_pfn = min(gap->end_pfn, start_pfn + pfn_cnt);
+ pgs_ol = end_pfn - start_pfn;
+
+ /*
+ * hv_bring_pgs_online() identifies whether pfn
+ * should be online or not via checking pfn is in
+ * hot add covered range or gap range(Detail see
+ * has_pfn_is_backed()). So adjust gap before bringing
+ * online or add memory.
+ */
+ if (gap->end_pfn - gap->start_pfn == pgs_ol) {
+ list_del(&gap->list);
+ kfree(gap);
+ } else if (gap->start_pfn < start && gap->end_pfn == end_pfn) {
+ gap->end_pfn = start_pfn;
+ } else if (gap->end_pfn > end_pfn
+ && gap->start_pfn == start_pfn) {
+ gap->start_pfn = end_pfn;
+ } else {
+ gap->end_pfn = start_pfn;
+
+ new_gap = kzalloc(sizeof(struct hv_hotadd_gap),
+ GFP_ATOMIC);
+ if (!new_gap) {
+ do_hot_add = false;
+ return -ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&new_gap->list);
+ new_gap->start_pfn = end_pfn;
+ new_gap->end_pfn = gap->end_pfn;
+ list_add_tail(&gap->list, &has->gap_list);
+ }
+
+ /* Bring online or add memmory in gaps. */
+ for (pfn = start_pfn; pfn < end_pfn;
+ pfn = round_up(pfn + 1, block_pages)) {
+ pages = min(round_up(pfn + 1, block_pages),
+ end_pfn) - pfn;
+
+ if (online_section_nr(pfn_to_section_nr(pfn))) {
+ hv_bring_pgs_online(has, pfn, pages);
+ } else {
+ nid = memory_add_physaddr_to_nid(PFN_PHYS(pfn));
+ ret = add_memory(nid, PFN_PHYS(pfn),
+ round_up(pages, block_pages)
+ << PAGE_SHIFT);
+ if (ret) {
+ pr_err("Fail to add memory in gaps(error=%d).\n",
+ ret);
+ do_hot_add = false;
+ return ret;
+ }
+ }
+ }
+
+ start_pfn += pgs_ol;
+ pfn_cnt -= pgs_ol;
+ if (!pfn_cnt)
+ break;
+ }
+
+ return pg_cnt - pfn_cnt;
+}
+
static unsigned long handle_pg_range(unsigned long pg_start,
unsigned long pg_count)
{
@@ -975,6 +1061,22 @@ static unsigned long handle_pg_range(unsigned long pg_start,
old_covered_state = has->covered_end_pfn;
+ /*
+ * If start_pfn is less than cover_end_pfn, the hot-add memory
+ * area is in the gap range.
+ */
+ if (start_pfn < has->covered_end_pfn) {
+ pgs_ol = handle_hot_add_in_gap(start_pfn, pfn_cnt, has);
+
+ pfn_cnt -= pgs_ol;
+ if (!pfn_cnt) {
+ res = pgs_ol;
+ break;
+ }
+
+ start_pfn += pgs_ol;
+ }
+
if (start_pfn < has->ha_end_pfn) {
/*
* This is the case where we are backing pages
--
2.14.5
next prev parent reply other threads:[~2020-01-07 13:10 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-07 13:09 [RFC PATCH V2 00/10] x86/Hyper-V: Add Dynamic memory hot-remove function lantianyu1986
2020-01-07 13:09 ` [RFC PATCH V2 1/10] mm/resource: Move child to new resource when release mem region lantianyu1986
2020-01-20 18:34 ` Michael Kelley
2020-01-20 19:20 ` Michael Kelley
2020-01-07 13:09 ` [RFC PATCH V2 2/10] mm: expose is_mem_section_removable() symbol lantianyu1986
2020-01-07 13:36 ` Michal Hocko
2020-01-10 13:41 ` David Hildenbrand
2020-01-13 14:49 ` [EXTERNAL] " Tianyu Lan
2020-01-13 15:01 ` David Hildenbrand
2020-01-14 9:50 ` Michal Hocko
2020-01-17 16:35 ` Tianyu Lan
2020-01-20 14:14 ` Michal Hocko
2020-01-07 13:09 ` [RFC PATCH V2 3/10] x86/Hyper-V/Balloon: Replace hot-add and balloon up works with a common work lantianyu1986
2020-01-20 19:12 ` Michael Kelley
2020-01-07 13:09 ` [RFC PATCH V2 4/10] x86/Hyper-V/Balloon: Convert spin lock ha_lock to mutex lantianyu1986
2020-01-07 13:09 ` [RFC PATCH V2 5/10] x86/Hyper-V/Balloon: Avoid releasing ha_lock when traverse ha_region_list lantianyu1986
2020-01-07 13:09 ` [RFC PATCH V2 6/10] x86/Hyper-V/Balloon: Enable mem hot-remove capability lantianyu1986
2020-01-07 13:09 ` [RFC PATCH V2 7/10] x86/Hyper-V/Balloon: Handle mem hot-remove request lantianyu1986
2020-01-07 13:09 ` [RFC PATCH V2 8/10] x86/Hyper-V/Balloon: Handle request with non-aligned page number lantianyu1986
2020-01-07 13:09 ` lantianyu1986 [this message]
2020-01-07 13:09 ` [RFC PATCH V2 10/10] x86/Hyper-V: Workaround Hyper-V unballoon msg bug lantianyu1986
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=20200107130950.2983-10-Tianyu.Lan@microsoft.com \
--to=lantianyu1986@gmail.com \
--cc=Tianyu.Lan@microsoft.com \
--cc=david@redhat.com \
--cc=eric.devolder@oracle.com \
--cc=haiyangz@microsoft.com \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=michael.h.kelley@microsoft.com \
--cc=sashal@kernel.org \
--cc=sthemmin@microsoft.com \
--cc=vkuznets@redhat.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).