jbd2: Remove a large array of bh's from the stack of the checkpoint routine
jbd2_log_do_checkpoint()n is one of the kernel's largest stack users.
Move the array of buffer head's from the stack of jbd2_log_do_checkpoint()
to the in-core journal structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index a3cd647..004c9a8 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -687,6 +687,8 @@
return end + (MAX_JIFFY_OFFSET - start);
}
+#define JBD2_NR_BATCH 64
+
/**
* struct journal_s - The journal_s type is the concrete type associated with
* journal_t.
@@ -831,6 +833,14 @@
struct mutex j_checkpoint_mutex;
/*
+ * List of buffer heads used by the checkpoint routine. This
+ * was moved from jbd2_log_do_checkpoint() to reduce stack
+ * usage. Access to this array is controlled by the
+ * j_checkpoint_mutex. [j_checkpoint_mutex]
+ */
+ struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
+
+ /*
* Journal head: identifies the first unused block in the journal.
* [j_state_lock]
*/