The patch titled
Subject: xen, mm: allow deferred page initialization for xen pv domains
has been removed from the -mm tree. Its filename was
xen-mm-allow-deferred-page-initialization-for-xen-pv-domains.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Subject: xen, mm: allow deferred page initialization for xen pv domains
Juergen Gross noticed that f7f99100d8d ("mm: stop zeroing memory during
allocation in vmemmap") broke XEN PV domains when deferred struct page
initialization is enabled.
This is because the xen's PagePinned() flag is getting erased from struct
pages when they are initialized later in boot.
Juergen fixed this problem by disabling deferred pages on xen pv domains.
It is desirable, however, to have this feature available as it reduces
boot time. This fix re-enables the feature for pv-dmains, and fixes the
problem the following way:
The fix is to delay setting PagePinned flag until struct pages for all
allocated memory are initialized, i.e. until after free_all_bootmem().
A new x86_init.hyper op init_after_bootmem() is called to let xen know
that boot allocator is done, and hence struct pages for all the allocated
memory are now initialized. If deferred page initialization is enabled,
the rest of struct pages are going to be initialized later in boot once
page_alloc_init_late() is called.
xen_after_bootmem() walks page table's pages and marks them pinned.
Link: http://lkml.kernel.org/r/20180226160112.24724-2-pasha.tatashin@xxxxxxxxxx
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Tested-by: Juergen Gross <jgross@xxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Alok Kataria <akataria@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Jinbum Park <jinb.park7@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Jia Zhang <zhang.jia@xxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/x86_init.h | 2 +
arch/x86/kernel/x86_init.c | 1
arch/x86/mm/init_32.c | 1
arch/x86/mm/init_64.c | 1
arch/x86/xen/mmu_pv.c | 38 ++++++++++++++++++++----------
mm/page_alloc.c | 4 ---
6 files changed, 31 insertions(+), 16 deletions(-)
diff -puN arch/x86/include/asm/x86_init.h~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains arch/x86/include/asm/x86_init.h
--- a/arch/x86/include/asm/x86_init.h~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/arch/x86/include/asm/x86_init.h
@@ -122,12 +122,14 @@ struct x86_init_pci {
* @guest_late_init: guest late init
* @x2apic_available: X2APIC detection
* @init_mem_mapping: setup early mappings during init_mem_mapping()
+ * @init_after_bootmem: guest init after boot allocator is finished
*/
struct x86_hyper_init {
void (*init_platform)(void);
void (*guest_late_init)(void);
bool (*x2apic_available)(void);
void (*init_mem_mapping)(void);
+ void (*init_after_bootmem)(void);
};
/**
diff -puN arch/x86/kernel/x86_init.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains arch/x86/kernel/x86_init.c
--- a/arch/x86/kernel/x86_init.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/arch/x86/kernel/x86_init.c
@@ -92,6 +92,7 @@ struct x86_init_ops x86_init __initdata
.guest_late_init = x86_init_noop,
.x2apic_available = bool_x86_init_noop,
.init_mem_mapping = x86_init_noop,
+ .init_after_bootmem = x86_init_noop,
},
.acpi = {
diff -puN arch/x86/mm/init_32.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains arch/x86/mm/init_32.c
--- a/arch/x86/mm/init_32.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/arch/x86/mm/init_32.c
@@ -778,6 +778,7 @@ void __init mem_init(void)
free_all_bootmem();
after_bootmem = 1;
+ x86_init.hyper.init_after_bootmem();
mem_init_print_info(NULL);
printk(KERN_INFO "virtual kernel memory layout:\n"
diff -puN arch/x86/mm/init_64.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/arch/x86/mm/init_64.c
@@ -1185,6 +1185,7 @@ void __init mem_init(void)
/* this will put all memory onto the freelists */
free_all_bootmem();
after_bootmem = 1;
+ x86_init.hyper.init_after_bootmem();
/*
* Must be done after boot memory is put on freelist, because here we
diff -puN arch/x86/xen/mmu_pv.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains arch/x86/xen/mmu_pv.c
--- a/arch/x86/xen/mmu_pv.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/arch/x86/xen/mmu_pv.c
@@ -116,6 +116,8 @@ DEFINE_PER_CPU(unsigned long, xen_curren
static phys_addr_t xen_pt_base, xen_pt_size __initdata;
+static DEFINE_STATIC_KEY_FALSE(xen_struct_pages_ready);
+
/*
* Just beyond the highest usermode address. STACK_TOP_MAX has a
* redzone above it, so round it up to a PGD boundary.
@@ -155,11 +157,18 @@ void make_lowmem_page_readwrite(void *va
}
+/*
+ * During early boot all page table pages are pinned, but we do not have struct
+ * pages, so return true until struct pages are ready.
+ */
static bool xen_page_pinned(void *ptr)
{
- struct page *page = virt_to_page(ptr);
+ if (static_branch_likely(&xen_struct_pages_ready)) {
+ struct page *page = virt_to_page(ptr);
- return PagePinned(page);
+ return PagePinned(page);
+ }
+ return true;
}
static void xen_extend_mmu_update(const struct mmu_update *update)
@@ -836,11 +845,6 @@ void xen_mm_pin_all(void)
spin_unlock(&pgd_lock);
}
-/*
- * The init_mm pagetable is really pinned as soon as its created, but
- * that's before we have page structures to store the bits. So do all
- * the book-keeping now.
- */
static int __init xen_mark_pinned(struct mm_struct *mm, struct page *page,
enum pt_level level)
{
@@ -848,8 +852,18 @@ static int __init xen_mark_pinned(struct
return 0;
}
-static void __init xen_mark_init_mm_pinned(void)
+/*
+ * The init_mm pagetable is really pinned as soon as its created, but
+ * that's before we have page structures to store the bits. So do all
+ * the book-keeping now once struct pages for allocated pages are
+ * initialized. This happens only after free_all_bootmem() is called.
+ */
+static void __init xen_after_bootmem(void)
{
+ static_branch_enable(&xen_struct_pages_ready);
+#ifdef CONFIG_X86_64
+ SetPagePinned(virt_to_page(level3_user_vsyscall));
+#endif
xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
}
@@ -1623,14 +1637,15 @@ static inline void __set_pfn_prot(unsign
static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn,
unsigned level)
{
- bool pinned = PagePinned(virt_to_page(mm->pgd));
+ bool pinned = xen_page_pinned(mm->pgd);
trace_xen_mmu_alloc_ptpage(mm, pfn, level, pinned);
if (pinned) {
struct page *page = pfn_to_page(pfn);
- SetPagePinned(page);
+ if (static_branch_likely(&xen_struct_pages_ready))
+ SetPagePinned(page);
if (!PageHighMem(page)) {
xen_mc_batch();
@@ -2364,9 +2379,7 @@ static void __init xen_post_allocator_in
#ifdef CONFIG_X86_64
pv_mmu_ops.write_cr3 = &xen_write_cr3;
- SetPagePinned(virt_to_page(level3_user_vsyscall));
#endif
- xen_mark_init_mm_pinned();
}
static void xen_leave_lazy_mmu(void)
@@ -2450,6 +2463,7 @@ static const struct pv_mmu_ops xen_mmu_o
void __init xen_init_mmu_ops(void)
{
x86_init.paging.pagetable_init = xen_pagetable_init;
+ x86_init.hyper.init_after_bootmem = xen_after_bootmem;
pv_mmu_ops = xen_mmu_ops;
diff -puN mm/page_alloc.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains mm/page_alloc.c
--- a/mm/page_alloc.c~xen-mm-allow-deferred-page-initialization-for-xen-pv-domains
+++ a/mm/page_alloc.c
@@ -46,7 +46,6 @@
#include <linux/stop_machine.h>
#include <linux/sort.h>
#include <linux/pfn.h>
-#include <xen/xen.h>
#include <linux/backing-dev.h>
#include <linux/fault-inject.h>
#include <linux/page-isolation.h>
@@ -317,9 +316,6 @@ static inline bool update_defer_init(pg_
/* Always populate low zones for address-constrained allocations */
if (zone_end < pgdat_end_pfn(pgdat))
return true;
- /* Xen PV domains need page structures early */
- if (xen_pv_domain())
- return true;
(*nr_initialised)++;
if ((*nr_initialised > pgdat->static_init_pgcnt) &&
(pfn & (PAGES_PER_SECTION - 1)) == 0) {
_
Patches currently in -mm which might be from pasha.tatashin@xxxxxxxxxx are
sparc64-ng4-memset-32-bits-overflow.patch
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