This patch addeds a sysctl entry for changing the journal commit interval
for ext3.
It's extracted from the -tmcitk (too many chefs in the kitchen) and the
-jrua (Joe random useless acronym) trees.
Stephen, can you take a look at this and tell me if the locking is sane and
safe for ext3? I looked it over for some time and ran it in several
configurations without error but I'd consider the locking about as safe as
a Rusty Russell patch swinging a chainsaw until you gave it a look.
diff -Nru a/fs/jbd/journal.c b/fs/jbd/journal.c
--- a/fs/jbd/journal.c Wed Jul 24 17:38:08 2002
+++ b/fs/jbd/journal.c Wed Jul 24 17:38:08 2002
@@ -36,6 +36,7 @@
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/proc_fs.h>
+#include <linux/sysctl.h>
EXPORT_SYMBOL(journal_start);
EXPORT_SYMBOL(journal_try_start);
@@ -195,6 +196,66 @@
journal_t *current_journal; // AKPM: debug
+/* sysctl variable for changing the commit interval on all journals */
+int journal_commit_interval = 5;
+
+#ifdef CONFIG_SYSCTL
+/*
+ * Change the value of journal_commit_interval and then change the
+ * corresponding value in every journal. This function also resets
+ * the commit timers for the journal.
+ * -- Cort <cort@fsmlabs.com>
+ */
+int journal_dointvec(ctl_table *table, int write, struct file *filp,
+ void *buffer, size_t *lenp)
+{
+ int i;
+ struct list_head *list;
+
+ /* do the normal parsing to get an int */
+ if ( (i = proc_dointvec(table,write,filp,buffer,lenp)) )
+ return i;
+
+ /* we have the new value, change it in all journals */
+ list_for_each(list, &all_journals)
+ {
+ unsigned long new_expires;
+
+ journal_t *journal =
+ list_entry(list, journal_t, j_all_journals);
+
+ lock_journal(journal);
+
+ /* compute the new expire time */
+ new_expires = (journal->j_commit_timer->expires -
+ journal->j_commit_interval) +
+ (journal_commit_interval*HZ);
+
+ /* set the new interval */
+ journal->j_commit_interval =
+ journal_commit_interval*HZ;
+
+ /* set the new expire for the transaction */
+ if ( journal->j_running_transaction )
+ journal->j_running_transaction->t_expires =
+ new_expires;
+
+ /* Adjust each timer for the new interval taking
+ * into account how long it has already been since
+ * the last commit. We don't modify timers that
+ * are not already active since they get set and
+ * activated elsewhere when they're needed.
+ */
+ if ( journal->j_commit_timer_active )
+ mod_timer( journal->j_commit_timer, new_expires );
+
+ unlock_journal(journal);
+ }
+
+ return 0;
+}
+#endif /* CONFIG_SYSCTL */
+
int kjournald(void *arg)
{
journal_t *journal = (journal_t *) arg;
@@ -688,7 +749,7 @@
init_MUTEX(&journal->j_checkpoint_sem);
init_MUTEX(&journal->j_sem);
- journal->j_commit_interval = (HZ * 5);
+ journal->j_commit_interval = journal_commit_interval*HZ;
/* The journal is marked for error until we succeed with recovery! */
journal->j_flags = JFS_ABORT;
diff -Nru a/include/linux/sysctl.h b/include/linux/sysctl.h
--- a/include/linux/sysctl.h Wed Jul 24 17:38:08 2002
+++ b/include/linux/sysctl.h Wed Jul 24 17:38:08 2002
@@ -543,6 +543,7 @@
FS_LEASES=13, /* int: leases enabled */
FS_DIR_NOTIFY=14, /* int: directory notification enabled */
FS_LEASE_TIME=15, /* int: maximum time to wait for a lease break */
+ FS_JOURNAL_TIMEOUT=16, /* int: time between journal commits */
};
/* CTL_DEBUG names: */
diff -Nru a/kernel/sysctl.c b/kernel/sysctl.c
--- a/kernel/sysctl.c Wed Jul 24 17:38:07 2002
+++ b/kernel/sysctl.c Wed Jul 24 17:38:07 2002
@@ -91,6 +91,12 @@
void *buffer, size_t *lenp);
#endif
+#ifdef CONFIG_EXT3_FS
+extern int journal_commit_interval;
+int journal_dointvec(ctl_table *, int, struct file *, void *, size_t *);
+#endif /* CONFIG_EXT3_FS */
+
+
#ifdef CONFIG_BSD_PROCESS_ACCT
extern int acct_parm[];
#endif
@@ -306,6 +312,10 @@
sizeof(int), 0644, NULL, &proc_dointvec},
{FS_LEASE_TIME, "lease-break-time", &lease_break_time, sizeof(int),
0644, NULL, &proc_dointvec},
+#ifdef CONFIG_EXT3_FS
+ {FS_JOURNAL_TIMEOUT, "journal-commit-interval",
+ &journal_commit_interval, sizeof(int), 0644, NULL, &journal_dointvec},
+#endif /* CONFIG_EXT3_FS */
{0}
};
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Jul 30 2002 - 14:00:18 EST