powerpc/pseries/cmm: Implement balloon compaction (fe030c9b) · Commits · 戴 / test

arch/powerpc/platforms/pseries/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -108,6 +108,7 @@ config PPC_SMLPAR
		config CMM
		tristate "Collaborative memory management"
		depends on PPC_SMLPAR
		select MEMORY_BALLOON
		default y
		help
		Select this option, if you want to enable the kernel interface

arch/powerpc/platforms/pseries/cmm.c

+119 −14

Original line number	Diff line number	Diff line
		@@ -19,6 +19,10 @@
		#include <linux/stringify.h>
		#include <linux/swap.h>
		#include <linux/device.h>
		#include <linux/mount.h>
		#include <linux/pseudo_fs.h>
		#include <linux/magic.h>
		#include <linux/balloon_compaction.h>
		#include <asm/firmware.h>
		#include <asm/hvcall.h>
		#include <asm/mmu.h>
		@@ -77,13 +81,11 @@ static atomic_long_t loaned_pages;
		static unsigned long loaned_pages_target;
		static unsigned long oom_freed_pages;

		static LIST_HEAD(cmm_page_list);
		static DEFINE_SPINLOCK(cmm_lock);

		static DEFINE_MUTEX(hotplug_mutex);
		static int hotplug_occurred; /* protected by the hotplug mutex */

		static struct task_struct *cmm_thread_ptr;
		static struct balloon_dev_info b_dev_info;

		static long plpar_page_set_loaned(struct page *page)
		{
		@@ -149,19 +151,16 @@ static long cmm_alloc_pages(long nr)
		__GFP_NOMEMALLOC);
		if (!page)
		break;
		spin_lock(&cmm_lock);
		rc = plpar_page_set_loaned(page);
		if (rc) {
		pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc);
		spin_unlock(&cmm_lock);
		__free_page(page);
		break;
		}

		list_add(&page->lru, &cmm_page_list);
		balloon_page_enqueue(&b_dev_info, page);
		atomic_long_inc(&loaned_pages);
		adjust_managed_page_count(page, -1);
		spin_unlock(&cmm_lock);
		nr--;
		}

		@@ -178,21 +177,19 @@ static long cmm_alloc_pages(long nr)
		**/
		static long cmm_free_pages(long nr)
		{
		struct page page, tmp;
		struct page *page;

		cmm_dbg("Begin free of %ld pages.\n", nr);
		spin_lock(&cmm_lock);
		list_for_each_entry_safe(page, tmp, &cmm_page_list, lru) {
		if (!nr)
		while (nr) {
		page = balloon_page_dequeue(&b_dev_info);
		if (!page)
		break;
		plpar_page_set_active(page);
		list_del(&page->lru);
		adjust_managed_page_count(page, 1);
		__free_page(page);
		atomic_long_dec(&loaned_pages);
		nr--;
		}
		spin_unlock(&cmm_lock);
		cmm_dbg("End request with %ld pages unfulfilled\n", nr);
		return nr;
		}
		@@ -484,6 +481,106 @@ static struct notifier_block cmm_mem_nb = {
		.priority = CMM_MEM_HOTPLUG_PRI
		};

		#ifdef CONFIG_BALLOON_COMPACTION
		static struct vfsmount *balloon_mnt;

		static int cmm_init_fs_context(struct fs_context *fc)
		{
		return init_pseudo(fc, PPC_CMM_MAGIC) ? 0 : -ENOMEM;
		}

		static struct file_system_type balloon_fs = {
		.name = "ppc-cmm",
		.init_fs_context = cmm_init_fs_context,
		.kill_sb = kill_anon_super,
		};

		static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
		struct page newpage, struct page page,
		enum migrate_mode mode)
		{
		unsigned long flags;

		/*
		* loan/"inflate" the newpage first.
		*
		* We might race against the cmm_thread who might discover after our
		* loan request that another page is to be unloaned. However, once
		* the cmm_thread runs again later, this error will automatically
		* be corrected.
		*/
		if (plpar_page_set_loaned(newpage)) {
		/* Unlikely, but possible. Tell the caller not to retry now. */
		pr_err_ratelimited("%s: Cannot set page to loaned.", __func__);
		return -EBUSY;
		}

		/* balloon page list reference */
		get_page(newpage);

		spin_lock_irqsave(&b_dev_info->pages_lock, flags);
		balloon_page_insert(b_dev_info, newpage);
		balloon_page_delete(page);
		b_dev_info->isolated_pages--;
		spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);

		/*
		* activate/"deflate" the old page. We ignore any errors just like the
		* other callers.
		*/
		plpar_page_set_active(page);

		/* balloon page list reference */
		put_page(page);

		return MIGRATEPAGE_SUCCESS;
		}

		static int cmm_balloon_compaction_init(void)
		{
		int rc;

		balloon_devinfo_init(&b_dev_info);
		b_dev_info.migratepage = cmm_migratepage;

		balloon_mnt = kern_mount(&balloon_fs);
		if (IS_ERR(balloon_mnt)) {
		rc = PTR_ERR(balloon_mnt);
		balloon_mnt = NULL;
		return rc;
		}

		b_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
		if (IS_ERR(b_dev_info.inode)) {
		rc = PTR_ERR(b_dev_info.inode);
		b_dev_info.inode = NULL;
		kern_unmount(balloon_mnt);
		balloon_mnt = NULL;
		return rc;
		}

		b_dev_info.inode->i_mapping->a_ops = &balloon_aops;
		return 0;
		}
		static void cmm_balloon_compaction_deinit(void)
		{
		if (b_dev_info.inode)
		iput(b_dev_info.inode);
		b_dev_info.inode = NULL;
		kern_unmount(balloon_mnt);
		balloon_mnt = NULL;
		}
		#else /* CONFIG_BALLOON_COMPACTION */
		static int cmm_balloon_compaction_init(void)
		{
		return 0;
		}

		static void cmm_balloon_compaction_deinit(void)
		{
		}
		#endif /* CONFIG_BALLOON_COMPACTION */

		/**
		* cmm_init - Module initialization
		*
		@@ -497,9 +594,14 @@ static int cmm_init(void)
		if (!firmware_has_feature(FW_FEATURE_CMO))
		return -EOPNOTSUPP;

		if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
		rc = cmm_balloon_compaction_init();
		if (rc)
		return rc;

		rc = register_oom_notifier(&cmm_oom_nb);
		if (rc < 0)
		goto out_balloon_compaction;

		if ((rc = register_reboot_notifier(&cmm_reboot_nb)))
		goto out_oom_notifier;

		@@ -527,6 +629,8 @@ out_reboot_notifier:
		unregister_reboot_notifier(&cmm_reboot_nb);
		out_oom_notifier:
		unregister_oom_notifier(&cmm_oom_nb);
		out_balloon_compaction:
		cmm_balloon_compaction_deinit();
		return rc;
		}

		@@ -545,6 +649,7 @@ static void cmm_exit(void)
		unregister_memory_notifier(&cmm_mem_nb);
		cmm_free_pages(atomic_long_read(&loaned_pages));
		cmm_unregister_sysfs(&cmm_dev);
		cmm_balloon_compaction_deinit();
		}

		/**

include/uapi/linux/magic.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -94,5 +94,6 @@
		#define ZSMALLOC_MAGIC 0x58295829
		#define DMA_BUF_MAGIC 0x444d4142 /* "DMAB" */
		#define Z3FOLD_MAGIC 0x33
		#define PPC_CMM_MAGIC 0xc7571590

		#endif /* __LINUX_MAGIC_H__ */

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