1021.lowlatency.patch

sm86xx内核源包括补丁（ GPL ）的

 	
- repeat:
 	list_for_each_prev(p, list) {
+		if (TEST_RESCHED_COUNT(32)) {
+			RESET_RESCHED_COUNT();
+			if (conditional_schedule_needed()) {
+				spin_unlock(&lru_list_lock);
+				goto repeat;
+			}
+		}
 		bh = BH_ENTRY(p);
 		if (buffer_locked(bh)) {
 			get_bh(bh);
@@ -973,7 +1029,6 @@
 			if (!buffer_uptodate(bh))
 				err = -EIO;
 			brelse(bh);
-			spin_lock(&lru_list_lock);
 			goto repeat;
 		}
 	}
@@ -990,12 +1045,24 @@
 void invalidate_inode_buffers(struct inode *inode)
 {
 	struct list_head * entry;
-	
+
+repeat:
+	conditional_schedule();
 	spin_lock(&lru_list_lock);
-	while ((entry = inode->i_dirty_buffers.next) != &inode->i_dirty_buffers)
+	while ((entry = inode->i_dirty_buffers.next) != &inode->i_dirty_buffers) {
+		if (conditional_schedule_needed()) {
+			spin_unlock(&lru_list_lock);
+			goto repeat;
+		}
 		remove_inode_queue(BH_ENTRY(entry));
-	while ((entry = inode->i_dirty_data_buffers.next) != &inode->i_dirty_data_buffers)
+	}
+	while ((entry = inode->i_dirty_data_buffers.next) != &inode->i_dirty_data_buffers) {
+		if (conditional_schedule_needed()) {
+			spin_unlock(&lru_list_lock);
+			goto repeat;
+		}
 		remove_inode_queue(BH_ENTRY(entry));
+	}
 	spin_unlock(&lru_list_lock);
 }
 
@@ -1018,6 +1085,7 @@
 		bh = get_hash_table(dev, block, size);
 		if (bh) {
 			touch_buffer(bh);
+			conditional_schedule();
 			return bh;
 		}
 
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/dcache.c linuxmips-2.4.30/fs/dcache.c
--- linuxmips-2.4.30.ref/fs/dcache.c	2004-11-18 16:28:47.000000000 -0800
+++ linuxmips-2.4.30/fs/dcache.c	2005-07-22 09:36:02.000000000 -0700
@@ -324,11 +324,23 @@
  
 void prune_dcache(int count)
 {
+	DEFINE_RESCHED_COUNT;
+
+redo:
 	spin_lock(&dcache_lock);
 	for (;;) {
 		struct dentry *dentry;
 		struct list_head *tmp;
 
+		if (TEST_RESCHED_COUNT(100)) {
+			RESET_RESCHED_COUNT();
+			if (conditional_schedule_needed()) {
+				spin_unlock(&dcache_lock);
+				unconditional_schedule();
+				goto redo;
+			}
+		}
+
 		tmp = dentry_unused.prev;
 
 		if (tmp == &dentry_unused)
@@ -483,6 +495,7 @@
 	struct dentry *this_parent = parent;
 	struct list_head *next;
 	int found = 0;
+	DEFINE_RESCHED_COUNT;
 
 	spin_lock(&dcache_lock);
 repeat:
@@ -497,6 +510,13 @@
 			list_add(&dentry->d_lru, dentry_unused.prev);
 			found++;
 		}
+
+		if (TEST_RESCHED_COUNT(500) && found > 10) {
+			if (conditional_schedule_needed())	/* Typically sys_rmdir() */
+				goto out;
+			RESET_RESCHED_COUNT();
+		}
+
 		/*
 		 * Descend a level if the d_subdirs list is non-empty.
 		 */
@@ -521,6 +541,7 @@
 #endif
 		goto resume;
 	}
+out:
 	spin_unlock(&dcache_lock);
 	return found;
 }
@@ -536,8 +557,10 @@
 {
 	int found;
 
-	while ((found = select_parent(parent)) != 0)
+	while ((found = select_parent(parent)) != 0) {
 		prune_dcache(found);
+		conditional_schedule();		/* Typically sys_rmdir() */
+	}
 }
 
 /*
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/exec.c linuxmips-2.4.30/fs/exec.c
--- linuxmips-2.4.30.ref/fs/exec.c	2005-07-21 19:15:31.000000000 -0700
+++ linuxmips-2.4.30/fs/exec.c	2005-07-22 09:36:02.000000000 -0700
@@ -245,7 +245,7 @@
 					memset(kaddr+offset+len, 0,
 						PAGE_SIZE-offset-len);
 			}
-			err = copy_from_user(kaddr+offset, str, bytes_to_copy);
+			err = ll_copy_from_user(kaddr+offset, str, bytes_to_copy);
 			if (err) {
 				ret = -EFAULT;
 				goto out;
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/ext2/dir.c linuxmips-2.4.30/fs/ext2/dir.c
--- linuxmips-2.4.30.ref/fs/ext2/dir.c	2005-04-05 12:09:57.000000000 -0700
+++ linuxmips-2.4.30/fs/ext2/dir.c	2005-07-22 09:36:02.000000000 -0700
@@ -153,6 +153,7 @@
 	struct address_space *mapping = dir->i_mapping;
 	struct page *page = read_cache_page(mapping, n,
 				(filler_t*)mapping->a_ops->readpage, NULL);
+	conditional_schedule();		/* Scanning large directories */
 	if (!IS_ERR(page)) {
 		wait_on_page(page);
 		kmap(page);
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/ext2/inode.c linuxmips-2.4.30/fs/ext2/inode.c
--- linuxmips-2.4.30.ref/fs/ext2/inode.c	2004-08-14 11:39:01.000000000 -0700
+++ linuxmips-2.4.30/fs/ext2/inode.c	2005-07-22 09:36:02.000000000 -0700
@@ -727,8 +727,13 @@
 {
 	unsigned long block_to_free = 0, count = 0;
 	unsigned long nr;
+	DEFINE_RESCHED_COUNT;
 
 	for ( ; p < q ; p++) {
+		if (TEST_RESCHED_COUNT(32)) {
+			RESET_RESCHED_COUNT();
+			conditional_schedule();
+		}
 		nr = le32_to_cpu(*p);
 		if (nr) {
 			*p = 0;
@@ -771,6 +776,7 @@
 	if (depth--) {
 		int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
 		for ( ; p < q ; p++) {
+			conditional_schedule();		/* Deleting large files */
 			nr = le32_to_cpu(*p);
 			if (!nr)
 				continue;
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/ext3/balloc.c linuxmips-2.4.30/fs/ext3/balloc.c
--- linuxmips-2.4.30.ref/fs/ext3/balloc.c	2003-07-04 20:23:44.000000000 -0700
+++ linuxmips-2.4.30/fs/ext3/balloc.c	2005-07-22 09:36:02.000000000 -0700
@@ -363,6 +363,9 @@
 			}
 		}
 #endif
+		/* superblock lock is held, so this is safe */
+		conditional_schedule();
+
 		BUFFER_TRACE(bitmap_bh, "clear bit");
 		if (!ext3_clear_bit (bit + i, bitmap_bh->b_data)) {
 			ext3_error(sb, __FUNCTION__,
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/ext3/inode.c linuxmips-2.4.30/fs/ext3/inode.c
--- linuxmips-2.4.30.ref/fs/ext3/inode.c	2004-08-14 11:39:01.000000000 -0700
+++ linuxmips-2.4.30/fs/ext3/inode.c	2005-07-22 09:36:02.000000000 -0700
@@ -930,6 +930,8 @@
 
 	prev_blocks = inode->i_blocks;
 
+	conditional_schedule();		/* Reading large directories */
+
 	bh = ext3_getblk (handle, inode, block, create, err);
 	if (!bh)
 		return bh;
@@ -1633,6 +1635,7 @@
 	 */
 	for (p = first; p < last; p++) {
 		u32 nr = le32_to_cpu(*p);
+		conditional_schedule();
 		if (nr) {
 			struct buffer_head *bh;
 
@@ -1687,6 +1690,7 @@
 	}
 
 	for (p = first; p < last; p++) {
+		conditional_schedule();
 		nr = le32_to_cpu(*p);
 		if (nr) {
 			/* accumulate blocks to free if they're contiguous */
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/ext3/namei.c linuxmips-2.4.30/fs/ext3/namei.c
--- linuxmips-2.4.30.ref/fs/ext3/namei.c	2003-02-25 14:03:11.000000000 -0800
+++ linuxmips-2.4.30/fs/ext3/namei.c	2005-07-22 09:36:02.000000000 -0700
@@ -157,6 +157,7 @@
 		if ((bh = bh_use[ra_ptr++]) == NULL)
 			goto next;
 		wait_on_buffer(bh);
+		conditional_schedule();
 		if (!buffer_uptodate(bh)) {
 			/* read error, skip block & hope for the best */
 			brelse(bh);
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/inode.c linuxmips-2.4.30/fs/inode.c
--- linuxmips-2.4.30.ref/fs/inode.c	2004-04-15 20:14:19.000000000 -0700
+++ linuxmips-2.4.30/fs/inode.c	2005-07-22 09:36:02.000000000 -0700
@@ -348,6 +348,8 @@
 
 	filemap_fdatawait(inode->i_mapping);
 
+	conditional_schedule();
+
 	spin_lock(&inode_lock);
 	inode->i_state &= ~I_LOCK;
 	__refile_inode(inode);
@@ -648,6 +650,7 @@
 	while (!list_empty(head)) {
 		struct inode *inode;
 
+		conditional_schedule();
 		inode = list_entry(head->next, struct inode, i_list);
 		list_del(&inode->i_list);
 
@@ -684,9 +687,22 @@
 		if (tmp == head)
 			break;
 		inode = list_entry(tmp, struct inode, i_list);
+
+		if (conditional_schedule_needed()) {
+			atomic_inc(&inode->i_count);
+			spin_unlock(&inode_lock);
+			unconditional_schedule();
+			spin_lock(&inode_lock);
+			atomic_dec(&inode->i_count);
+		}
+
 		if (inode->i_sb != sb)
 			continue;
+		atomic_inc(&inode->i_count);
+		spin_unlock(&inode_lock);
 		invalidate_inode_buffers(inode);
+		spin_lock(&inode_lock);
+		atomic_dec(&inode->i_count);
 		if (!atomic_read(&inode->i_count)) {
 			list_del_init(&inode->i_hash);
 			list_del(&inode->i_list);
@@ -796,15 +812,28 @@
 	int avg_pages;
 #endif
 	struct inode * inode;
+	int nr_to_scan = inodes_stat.nr_unused;
 
+resume:
 	spin_lock(&inode_lock);
-
 	count = 0;
 	entry = inode_unused.prev;
-	while (entry != &inode_unused)
-	{
+	while (entry != &inode_unused && nr_to_scan--) {
 		struct list_head *tmp = entry;
 
+		if (conditional_schedule_needed()) {
+			/*
+			 * Need to drop the lock.  Reposition
+			 * the list head so we start here next time.
+			 * This can corrupt the LRU nature of the
+			 * unused list, but this isn't very important.
+			 */
+			list_del(&inode_unused);
+			list_add(&inode_unused, entry);
+			spin_unlock(&inode_lock);
+			unconditional_schedule();
+			goto resume;
+		}
 		entry = entry->prev;
 		inode = INODE(tmp);
 		if (inode->i_state & (I_FREEING|I_CLEAR|I_LOCK))
@@ -1006,6 +1035,8 @@
 	if (inode) {
 		struct inode * old;
 
+		conditional_schedule();			/* sync_old_buffers */
+
 		spin_lock(&inode_lock);
 		/* We released the lock, so.. */
 		old = find_inode(sb, ino, head, find_actor, opaque);
diff -Naur --exclude=CVS --exclude='*.o' --exclude='*.a' --exclude='*.so' --exclude='*.elf' --exclude=System.map --exclude=Makefile.d --exclude='*log' --exclude='*log2' --exclude='*~' --exclude='.*~' --exclude='.#*' --exclude='*.bak' --exclude='*.orig' --exclude='*.rej' --exclude='core.[0-9]*' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=.depend --exclude='.*.o.flags' --exclude='*.gz' --exclude=vmlinux --exclude=vmlinux.bin --exclude=yamon-02.06-SIGMADESIGNS-01_el.bin linuxmips-2.4.30.ref/fs/jbd/checkpoint.c linuxmips-2.4.30/fs/jbd/checkpoint.c