mm: pin locked file after fault. [1/2]

PD#SWPL-95400

Problem:
If we pin a file in android, the whole data of this file
will be loaded to DDR, but most of these data may not be
used, this caused memory waste.

Solution:
delay mark mlocked flags for unevictable pages until
it has been faulted.
You can use following command to disable this function:
echo 0 > /proc/sys/vm/shrink_unevictable

Verify:
sc2_ah212

Change-Id: I05bb7654cc228604fe692429efbe40af713ca5c3
Signed-off-by: Jianxiong Pan <jianxiong.pan@amlogic.com>

mm/gup.c

@@ -21,6 +21,9 @@
 
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
 
 #include "internal.h"
 
@@ -624,6 +627,21 @@ retry:
 		 * when it attempts to reclaim the page.
 		 */
 		if (page->mapping && trylock_page(page)) {
+		#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+			struct address_space *mapping;
+
+			mapping = page_mapping(page);
+			if (mapping &&
+			    test_bit(AS_LOCK_MAPPING, &mapping->flags) &&
+			    sysctrl_shrink_unevictable) {
+				unlock_page(page);
+			} else {
+				/* same as #else */
+				lru_add_drain();
+				mlock_vma_page(page);
+				unlock_page(page);
+			}
+		#else
 			lru_add_drain();  /* push cached pages to LRU */
 			/*
 			 * Because we lock page here, and migration is
@@ -633,6 +651,7 @@ retry:
 			 */
 			mlock_vma_page(page);
 			unlock_page(page);
+		#endif
 		}
 	}
 out:

mm/memory.c

@@ -85,6 +85,12 @@
 #include <linux/uaccess.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
+#ifdef CONFIG_AMLOGIC_MEM_DEBUG
+#include <linux/amlogic/mem_debug.h>
+#endif
 
 #include "pgalloc-track.h"
 #include "internal.h"
@@ -4929,6 +4935,48 @@ unlock:
 	return 0;
 }
 
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+static bool __restore_locked_page(struct page *page, struct vm_area_struct *vma,
+			 unsigned long addr, void *arg)
+{
+	int ret;
+	pte_t old_pte, *pte;
+	spinlock_t *ptl;	/* pte lock */
+
+	if (vma->vm_flags & (VM_LOCKED | VM_LOCKONFAULT)) {
+		if (addr < vma->vm_start || addr >= vma->vm_end)
+			return -EFAULT;
+		if (!page_count(page))
+			return -EINVAL;
+
+		pte = get_locked_pte(vma->vm_mm, addr, &ptl);
+		if (!pte)
+			return true;
+		old_pte = *pte;
+		pte_unmap_unlock(pte, ptl);
+		/* already refaulted */
+		if (pte_valid(old_pte) && pte_pfn(old_pte) == page_to_pfn(page))
+			return true;
+
+		ret = insert_page(vma, addr, page, vma->vm_page_prot);
+		pr_debug("%s, restore page:%lx for addr:%lx, vma:%px, ret:%d, old_pte:%llx\n",
+			__func__,  page_to_pfn(page), addr, vma, ret,
+			(unsigned long long)pte_val(old_pte));
+		return ret ? false : true;
+	}
+	return true; /* keep loop */
+}
+
+static void restore_locked_page(struct page *page)
+{
+	struct rmap_walk_control rwc = {
+		.rmap_one = __restore_locked_page,
+	};
+
+	rmap_walk(page, &rwc);
+}
+#endif
+
 /*
  * By the time we get here, we already hold the mm semaphore
  *
@@ -4944,6 +4992,9 @@ static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 		.flags = flags,
 		.pgoff = linear_page_index(vma, address),
 		.gfp_mask = __get_fault_gfp_mask(vma),
+	#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+		.pte = NULL,
+	#endif
 	};
 	unsigned int dirty = flags & FAULT_FLAG_WRITE;
 	struct mm_struct *mm = vma->vm_mm;
@@ -5055,7 +5106,14 @@ static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 		if (!vmf.pte && uffd_missing_sigbus)
 			return VM_FAULT_SIGBUS;
 
-		return handle_pte_fault(&vmf);
+#ifdef CONFIG_AMLOGIC_MEM_DEBUG
+		ret = handle_pte_fault(&vmf);
+		if (!ret && vma->vm_flags & VM_LOCKED)
+			mlock_fault_size++;
+		return ret;
+#else
+ 		return handle_pte_fault(&vmf);
+#endif
 
 	spf_fail:
 		speculative_page_walk_end();
@@ -5185,7 +5243,25 @@ retry_pud:
 		}
 	}
 
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+	ret = handle_pte_fault(&vmf);
+	if (!ret) {
+		struct page *page = NULL;
+
+		page = aml_mlock_page_as_lock_mapping(vma, mm, &vmf, address);
+		if (page)
+			restore_locked_page(page);
+	}
+	return ret;
+#endif
+#ifdef CONFIG_AMLOGIC_MEM_DEBUG
+	ret = handle_pte_fault(&vmf);
+	if (!ret && vma->vm_flags & VM_LOCKED)
+		mlock_fault_size++;
+	return ret;
+#else
 	return handle_pte_fault(&vmf);
+#endif
 }
 
 /**

mm/migrate.c

@@ -54,6 +54,9 @@
 #include <linux/amlogic/aml_cma.h>
 #include <linux/delay.h>
 #endif
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
 
 #include <asm/tlbflush.h>
 
@@ -1295,6 +1298,10 @@ out:
 		else
 			put_page(newpage);
 	}
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+	if (reason == MR_CONTIG_RANGE && rc == MIGRATEPAGE_SUCCESS)
+		aml_clear_pin_locked_file(page);
+#endif
 
 	return rc;
 }

mm/mlock.c

@@ -25,6 +25,9 @@
 #include <linux/memcontrol.h>
 #include <linux/mm_inline.h>
 #include <linux/secretmem.h>
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
 
 #include "internal.h"
 
@@ -193,6 +196,7 @@ unsigned int munlock_vma_page(struct page *page)
 /*
  * convert get_user_pages() return value to posix mlock() error
  */
+#ifndef CONFIG_AMLOGIC_PIN_LOCKED_FILE_V2
 static int __mlock_posix_error_return(long retval)
 {
 	if (retval == -EFAULT)
@@ -201,6 +205,7 @@ static int __mlock_posix_error_return(long retval)
 		retval = -EAGAIN;
 	return retval;
 }
+#endif
 
 /*
  * Prepare page for fast batched LRU putback via putback_lru_evictable_pagevec()
@@ -588,6 +593,9 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
 		tmp = vma->vm_end;
 		if (tmp > end)
 			tmp = end;
+	#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+		reset_page_vma_flags(vma, flags);
+	#endif
 		error = mlock_fixup(vma, &prev, nstart, tmp, newflags);
 		if (error)
 			break;
@@ -686,9 +694,11 @@ static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t fla
 	if (error)
 		return error;
 
+#ifndef CONFIG_AMLOGIC_PIN_LOCKED_FILE_V2
 	error = __mm_populate(start, len, 0);
 	if (error)
 		return __mlock_posix_error_return(error);
+#endif
 	return 0;
 }
 

mm/rmap.c

@@ -80,6 +80,9 @@
 #include <trace/events/tlb.h>
 
 #include <trace/hooks/mm.h>
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
 
 #include "internal.h"
 
@@ -1471,8 +1474,14 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 			 * cleared).  But stop unmapping even in those cases.
 			 */
 			if (!PageTransCompound(page) || (PageHead(page) &&
-			     !PageDoubleMap(page) && !PageAnon(page)))
+			    !PageDoubleMap(page) && !PageAnon(page)))
+			#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+				/* only keep refault pages */
+				if (aml_is_pin_locked_file(page))
+					mlock_vma_page(page);
+			#else
 				mlock_vma_page(page);
+			#endif
 			page_vma_mapped_walk_done(&pvmw);
 			ret = false;
 			break;
@@ -2036,7 +2045,13 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
 			 * nor on an Anon THP (which may still be PTE-mapped
 			 * after DoubleMap was cleared).
 			 */
+		#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+			/* only keep refault pages */
+			if (aml_is_pin_locked_file(page))
+				mlock_vma_page(page);
+		#else
 			mlock_vma_page(page);
+		#endif
 			/*
 			 * No need to scan further once the page is marked
 			 * as mlocked.

mm/vmscan.c

@@ -77,6 +77,9 @@
 #ifdef CONFIG_AMLOGIC_CMA
 #include <linux/amlogic/aml_cma.h>
 #endif
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+#include <linux/amlogic/pin_file.h>
+#endif
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(mm_vmscan_direct_reclaim_begin);
 EXPORT_TRACEPOINT_SYMBOL_GPL(mm_vmscan_direct_reclaim_end);
@@ -1674,6 +1677,13 @@ retry:
 			enum ttu_flags flags = TTU_BATCH_FLUSH;
 			bool was_swapbacked = PageSwapBacked(page);
 
+#ifdef CONFIG_AMLOGIC_PIN_LOCKED_FILE
+			if (mapping &&
+			    test_bit(AS_LOCK_MAPPING, &mapping->flags) &&
+			    !aml_is_pin_locked_file(page) &&
+			    !PageMlocked(page))
+				flags |= TTU_IGNORE_MLOCK;
+#endif
 			if (unlikely(PageTransHuge(page)))
 				flags |= TTU_SPLIT_HUGE_PMD;