Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:
 "A few final bits:

   - large changes to vmalloc, yielding large performance benefits

   - tweak the console-flush-on-panic code

   - a few fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  panic: add an option to replay all the printk message in buffer
  initramfs: don't free a non-existent initrd
  fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount
  mm/compaction.c: correct zone boundary handling when isolating pages from a pageblock
  mm/vmap: add DEBUG_AUGMENT_LOWEST_MATCH_CHECK macro
  mm/vmap: add DEBUG_AUGMENT_PROPAGATE_CHECK macro
  mm/vmalloc.c: keep track of free blocks for vmap allocation

Documentation/admin-guide/kernel-parameters.txt

@@ -3212,6 +3212,7 @@
 			bit 2: print timer info
 			bit 3: print locks info if CONFIG_LOCKDEP is on
 			bit 4: print ftrace buffer
+			bit 5: print all printk messages in buffer
 
 	panic_on_warn	panic() instead of WARN().  Useful to cause kdump
 			on a WARN().

arch/powerpc/kernel/traps.c

@@ -179,7 +179,7 @@ extern void panic_flush_kmsg_end(void)
 	kmsg_dump(KMSG_DUMP_PANIC);
 	bust_spinlocks(0);
 	debug_locks_off();
-	console_flush_on_panic();
+	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
 }
 
 static unsigned long oops_begin(struct pt_regs *regs)

fs/fs-writeback.c

@@ -523,15 +523,16 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
 
 	isw->inode = inode;
 
-	atomic_inc(&isw_nr_in_flight);
-
 	/*
 	 * In addition to synchronizing among switchers, I_WB_SWITCH tells
 	 * the RCU protected stat update paths to grab the i_page
 	 * lock so that stat transfer can synchronize against them.
 	 * Let's continue after I_WB_SWITCH is guaranteed to be visible.
 	 */
 	call_rcu(&isw->rcu_head, inode_switch_wbs_rcu_fn);
+
+	atomic_inc(&isw_nr_in_flight);
+
 	goto out_unlock;
 
 out_free:
@@ -901,7 +902,11 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi,
 void cgroup_writeback_umount(void)
 {
 	if (atomic_read(&isw_nr_in_flight)) {
-		synchronize_rcu();
+		/*
+		 * Use rcu_barrier() to wait for all pending callbacks to
+		 * ensure that all in-flight wb switches are in the workqueue.
+		 */
+		rcu_barrier();
 		flush_workqueue(isw_wq);
 	}
 }

include/linux/console.h

@@ -166,6 +166,11 @@ struct console {
 extern int console_set_on_cmdline;
 extern struct console *early_console;
 
+enum con_flush_mode {
+	CONSOLE_FLUSH_PENDING,
+	CONSOLE_REPLAY_ALL,
+};
+
 extern int add_preferred_console(char *name, int idx, char *options);
 extern void register_console(struct console *);
 extern int unregister_console(struct console *);
@@ -175,7 +180,7 @@ extern int console_trylock(void);
 extern void console_unlock(void);
 extern void console_conditional_schedule(void);
 extern void console_unblank(void);
-extern void console_flush_on_panic(void);
+extern void console_flush_on_panic(enum con_flush_mode mode);
 extern struct tty_driver *console_device(int *);
 extern void console_stop(struct console *);
 extern void console_start(struct console *);

include/linux/vmalloc.h

@@ -50,12 +50,16 @@ struct vm_struct {
 struct vmap_area {
 	unsigned long va_start;
 	unsigned long va_end;
+
+	/*
+	 * Largest available free size in subtree.
+	 */
+	unsigned long subtree_max_size;
 	unsigned long flags;
 	struct rb_node rb_node;         /* address sorted rbtree */
 	struct list_head list;          /* address sorted list */
 	struct llist_node purge_list;    /* "lazy purge" list */
 	struct vm_struct *vm;
-	struct rcu_head rcu_head;
 };
 
 /*

init/initramfs.c

@@ -669,7 +669,7 @@ static int __init populate_rootfs(void)
 	 * If the initrd region is overlapped with crashkernel reserved region,
 	 * free only memory that is not part of crashkernel region.
 	 */
-	if (!do_retain_initrd && !kexec_free_initrd())
+	if (!do_retain_initrd && initrd_start && !kexec_free_initrd())
 		free_initrd_mem(initrd_start, initrd_end);
 	initrd_start = 0;
 	initrd_end = 0;

kernel/panic.c

@@ -51,6 +51,7 @@ EXPORT_SYMBOL_GPL(panic_timeout);
 #define PANIC_PRINT_TIMER_INFO		0x00000004
 #define PANIC_PRINT_LOCK_INFO		0x00000008
 #define PANIC_PRINT_FTRACE_INFO		0x00000010
+#define PANIC_PRINT_ALL_PRINTK_MSG	0x00000020
 unsigned long panic_print;
 
 ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
@@ -134,6 +135,9 @@ EXPORT_SYMBOL(nmi_panic);
 
 static void panic_print_sys_info(void)
 {
+	if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
+		console_flush_on_panic(CONSOLE_REPLAY_ALL);
+
 	if (panic_print & PANIC_PRINT_TASK_INFO)
 		show_state();
 
@@ -277,7 +281,7 @@ void panic(const char *fmt, ...)
 	 * panic() is not being callled from OOPS.
 	 */
 	debug_locks_off();
-	console_flush_on_panic();
+	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
 
 	panic_print_sys_info();
 

kernel/printk/printk.c

@@ -2535,10 +2535,11 @@ void console_unblank(void)
 
 /**
  * console_flush_on_panic - flush console content on panic
+ * @mode: flush all messages in buffer or just the pending ones
  *
  * Immediately output all pending messages no matter what.
  */
-void console_flush_on_panic(void)
+void console_flush_on_panic(enum con_flush_mode mode)
 {
 	/*
 	 * If someone else is holding the console lock, trylock will fail
@@ -2549,6 +2550,15 @@ void console_flush_on_panic(void)
 	 */
 	console_trylock();
 	console_may_schedule = 0;
+
+	if (mode == CONSOLE_REPLAY_ALL) {
+		unsigned long flags;
+
+		logbuf_lock_irqsave(flags);
+		console_seq = log_first_seq;
+		console_idx = log_first_idx;
+		logbuf_unlock_irqrestore(flags);
+	}
 	console_unlock();
 }
 

mm/compaction.c

@@ -1230,7 +1230,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn, unsigned long
 
 	/* Pageblock boundaries */
 	start_pfn = pageblock_start_pfn(pfn);
-	end_pfn = min(start_pfn + pageblock_nr_pages, zone_end_pfn(cc->zone));
+	end_pfn = min(pageblock_end_pfn(pfn), zone_end_pfn(cc->zone)) - 1;
 
 	/* Scan before */
 	if (start_pfn != pfn) {
@@ -1241,7 +1241,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn, unsigned long
 
 	/* Scan after */
 	start_pfn = pfn + nr_isolated;
-	if (start_pfn != end_pfn)
+	if (start_pfn < end_pfn)
 		isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false);
 
 	/* Skip this pageblock in the future as it's full or nearly full */