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authorLinus Torvalds <torvalds@linux-foundation.org>2021-03-26 21:15:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-03-26 21:15:25 +0300
commit6c20f6df61ee7b8b562143504cf3e89ae802de87 (patch)
treea72a9fccede5d829da51e6d44604c01943700075 /arch/x86/xen
parentf944d061f847b0ccf0ebc095b5a6ba9ea9caec4e (diff)
parentaf44a387e743ab7aa39d3fb5e29c0a973cf91bdc (diff)
downloadlinux-6c20f6df61ee7b8b562143504cf3e89ae802de87.tar.xz
Merge tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "This contains a small series with a more elegant fix of a problem which was originally fixed in rc2" * tag 'for-linus-5.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Revert "xen: fix p2m size in dom0 for disabled memory hotplug case" xen/x86: make XEN_BALLOON_MEMORY_HOTPLUG_LIMIT depend on MEMORY_HOTPLUG
Diffstat (limited to 'arch/x86/xen')
-rw-r--r--arch/x86/xen/p2m.c7
-rw-r--r--arch/x86/xen/setup.c16
2 files changed, 16 insertions, 7 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 17d80f751fcb..ac06ca32e9ef 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -98,8 +98,8 @@ EXPORT_SYMBOL_GPL(xen_p2m_size);
unsigned long xen_max_p2m_pfn __read_mostly;
EXPORT_SYMBOL_GPL(xen_max_p2m_pfn);
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
-#define P2M_LIMIT CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
+#ifdef CONFIG_XEN_MEMORY_HOTPLUG_LIMIT
+#define P2M_LIMIT CONFIG_XEN_MEMORY_HOTPLUG_LIMIT
#else
#define P2M_LIMIT 0
#endif
@@ -416,9 +416,6 @@ void __init xen_vmalloc_p2m_tree(void)
xen_p2m_last_pfn = xen_max_p2m_pfn;
p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
- if (!p2m_limit && IS_ENABLED(CONFIG_XEN_UNPOPULATED_ALLOC))
- p2m_limit = xen_start_info->nr_pages * XEN_EXTRA_MEM_RATIO;
-
vm.flags = VM_ALLOC;
vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
PMD_SIZE * PMDS_PER_MID_PAGE);
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 1a3b75652fa4..8bfc10330107 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -59,6 +59,18 @@ static struct {
} xen_remap_buf __initdata __aligned(PAGE_SIZE);
static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
+/*
+ * The maximum amount of extra memory compared to the base size. The
+ * main scaling factor is the size of struct page. At extreme ratios
+ * of base:extra, all the base memory can be filled with page
+ * structures for the extra memory, leaving no space for anything
+ * else.
+ *
+ * 10x seems like a reasonable balance between scaling flexibility and
+ * leaving a practically usable system.
+ */
+#define EXTRA_MEM_RATIO (10)
+
static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
static void __init xen_parse_512gb(void)
@@ -778,13 +790,13 @@ char * __init xen_memory_setup(void)
extra_pages += max_pages - max_pfn;
/*
- * Clamp the amount of extra memory to a XEN_EXTRA_MEM_RATIO
+ * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
* factor the base size.
*
* Make sure we have no memory above max_pages, as this area
* isn't handled by the p2m management.
*/
- extra_pages = min3(XEN_EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+ extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
extra_pages, max_pages - max_pfn);
i = 0;
addr = xen_e820_table.entries[0].addr;