[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1617140178-8773-6-git-send-email-anthony.yznaga@oracle.com>
Date: Tue, 30 Mar 2021 14:35:40 -0700
From: Anthony Yznaga <anthony.yznaga@...cle.com>
To: linux-mm@...ck.org, linux-kernel@...r.kernel.org
Cc: willy@...radead.org, corbet@....net, tglx@...utronix.de,
mingo@...hat.com, bp@...en8.de, x86@...nel.org, hpa@...or.com,
dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org,
rppt@...nel.org, akpm@...ux-foundation.org, hughd@...gle.com,
ebiederm@...ssion.com, keescook@...omium.org, ardb@...nel.org,
nivedita@...m.mit.edu, jroedel@...e.de, masahiroy@...nel.org,
nathan@...nel.org, terrelln@...com, vincenzo.frascino@....com,
martin.b.radev@...il.com, andreyknvl@...gle.com,
daniel.kiper@...cle.com, rafael.j.wysocki@...el.com,
dan.j.williams@...el.com, Jonathan.Cameron@...wei.com,
bhe@...hat.com, rminnich@...il.com, ashish.kalra@....com,
guro@...com, hannes@...xchg.org, mhocko@...nel.org,
iamjoonsoo.kim@....com, vbabka@...e.cz, alex.shi@...ux.alibaba.com,
david@...hat.com, richard.weiyang@...il.com,
vdavydov.dev@...il.com, graf@...zon.com, jason.zeng@...el.com,
lei.l.li@...el.com, daniel.m.jordan@...cle.com,
steven.sistare@...cle.com, linux-fsdevel@...r.kernel.org,
linux-doc@...r.kernel.org, kexec@...ts.infradead.org
Subject: [RFC v2 05/43] mm: PKRAM: support preserving transparent hugepages
Support preserving a transparent hugepage by recording the page order and
a flag indicating it is a THP. Use these values when the page is
restored to reconstruct the THP.
Signed-off-by: Anthony Yznaga <anthony.yznaga@...cle.com>
---
mm/pkram.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/mm/pkram.c b/mm/pkram.c
index 9c42db66d022..da44a6060c5f 100644
--- a/mm/pkram.c
+++ b/mm/pkram.c
@@ -21,6 +21,9 @@
#define PKRAM_ENTRY_FLAGS_SHIFT 0x5
#define PKRAM_ENTRY_FLAGS_MASK 0x7f
+#define PKRAM_ENTRY_ORDER_MASK 0x1f
+
+#define PKRAM_PAGE_TRANS_HUGE 0x1 /* page is a transparent hugepage */
/*
* Keeps references to data pages saved to PKRAM.
@@ -211,7 +214,11 @@ static void pkram_add_link_entry(struct pkram_data_stream *pds, struct page *pag
pkram_entry_t p;
short flags = 0;
+ if (PageTransHuge(page))
+ flags |= PKRAM_PAGE_TRANS_HUGE;
+
p = page_to_phys(page);
+ p |= compound_order(page);
p |= ((flags & PKRAM_ENTRY_FLAGS_MASK) << PKRAM_ENTRY_FLAGS_SHIFT);
link->entry[pds->entry_idx] = p;
pds->entry_idx++;
@@ -516,7 +523,7 @@ static int __pkram_save_page(struct pkram_access *pa, struct page *page,
pkram_add_link_entry(pds, page);
- pa->pages.next_index++;
+ pa->pages.next_index += compound_nr(page);
return 0;
}
@@ -542,19 +549,24 @@ int pkram_save_file_page(struct pkram_access *pa, struct page *page)
BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_SAVE);
- BUG_ON(PageCompound(page));
-
return __pkram_save_page(pa, page, page->index);
}
static struct page *__pkram_prep_load_page(pkram_entry_t p)
{
struct page *page;
+ int order;
short flags;
flags = (p >> PKRAM_ENTRY_FLAGS_SHIFT) & PKRAM_ENTRY_FLAGS_MASK;
page = pfn_to_page(PHYS_PFN(p));
+ if (flags & PKRAM_PAGE_TRANS_HUGE) {
+ order = p & PKRAM_ENTRY_ORDER_MASK;
+ prep_compound_page(page, order);
+ prep_transhuge_page(page);
+ }
+
return page;
}
@@ -588,7 +600,7 @@ static struct page *__pkram_load_page(struct pkram_access *pa, unsigned long *in
if (index) {
*index = pa->pages.next_index;
- pa->pages.next_index++;
+ pa->pages.next_index += compound_nr(page);
}
/* clear to avoid double free (see pkram_truncate_link()) */
--
1.8.3.1
Powered by blists - more mailing lists