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/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 9497718..adc08ec 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -249,16 +249,14 @@
return ret;
}
-#define NR_BATCH 64
-
static void
-__flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count)
+__flush_batch(journal_t *journal, int *batch_count)
{
int i;
- ll_rw_block(SWRITE, *batch_count, bhs);
+ ll_rw_block(SWRITE, *batch_count, journal->j_chkpt_bhs);
for (i = 0; i < *batch_count; i++) {
- struct buffer_head *bh = bhs[i];
+ struct buffer_head *bh = journal->j_chkpt_bhs[i];
clear_buffer_jwrite(bh);
BUFFER_TRACE(bh, "brelse");
__brelse(bh);
@@ -277,8 +275,7 @@
* Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
*/
static int __process_buffer(journal_t *journal, struct journal_head *jh,
- struct buffer_head **bhs, int *batch_count,
- transaction_t *transaction)
+ int *batch_count, transaction_t *transaction)
{
struct buffer_head *bh = jh2bh(jh);
int ret = 0;
@@ -325,14 +322,14 @@
get_bh(bh);
J_ASSERT_BH(bh, !buffer_jwrite(bh));
set_buffer_jwrite(bh);
- bhs[*batch_count] = bh;
+ journal->j_chkpt_bhs[*batch_count] = bh;
__buffer_relink_io(jh);
jbd_unlock_bh_state(bh);
transaction->t_chp_stats.cs_written++;
(*batch_count)++;
- if (*batch_count == NR_BATCH) {
+ if (*batch_count == JBD2_NR_BATCH) {
spin_unlock(&journal->j_list_lock);
- __flush_batch(journal, bhs, batch_count);
+ __flush_batch(journal, batch_count);
ret = 1;
}
}
@@ -388,7 +385,6 @@
if (journal->j_checkpoint_transactions == transaction &&
transaction->t_tid == this_tid) {
int batch_count = 0;
- struct buffer_head *bhs[NR_BATCH];
struct journal_head *jh;
int retry = 0, err;
@@ -402,7 +398,7 @@
retry = 1;
break;
}
- retry = __process_buffer(journal, jh, bhs, &batch_count,
+ retry = __process_buffer(journal, jh, &batch_count,
transaction);
if (retry < 0 && !result)
result = retry;
@@ -419,7 +415,7 @@
spin_unlock(&journal->j_list_lock);
retry = 1;
}
- __flush_batch(journal, bhs, &batch_count);
+ __flush_batch(journal, &batch_count);
}
if (retry) {