fs: mark lookup_slow() as noinline

mjguzik · brauner · commit 8d79ec9e7f63 · 2025-11-25T10:04:38.000+01:00
Otherwise it gets inlined notably in walk_component(), which convinces the compiler to push/pop additional registers in the fast path to accomodate existence of the inlined version. Shortens the fast path of that routine from 87 to 71 bytes. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://patch.msgid.link/20251119144930.2911698-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
diff --git a/fs/namei.c b/fs/namei.c
@@ -1863,7 +1863,7 @@ static struct dentry *__lookup_slow(const struct qstr *name,
 	return dentry;
 }
 
-static struct dentry *lookup_slow(const struct qstr *name,
+static noinline struct dentry *lookup_slow(const struct qstr *name,
 				  struct dentry *dir,
 				  unsigned int flags)
 {

Original file line number	Diff line number	Diff line change
`@@ -1863,7 +1863,7 @@ static struct dentry __lookup_slow(const struct qstr name,`
`1863`	`1863`	`return dentry;`
`1864`	`1864`	`}`
`1865`	`1865`
`1866`		`-static struct dentry lookup_slow(const struct qstr name,`
	`1866`	`+static noinline struct dentry lookup_slow(const struct qstr name,`
`1867`	`1867`	`struct dentry *dir,`
`1868`	`1868`	`unsigned int flags)`
`1869`	`1869`	`{`