"Trying to free nonexistent swap-page" error message.

From: Johan Simon Seland (johans@netfonds.no)
Date: Fri Jun 29 2001 - 03:15:10 EST


Hello,

I have searched the archives for this error message before, but no one
seems to have given a good answer. (Though the question has been
posted before.) I am not sure if this is a kernel problem, a hardware
problem or a Oracle problem. (Or a combination of them.)

One one of our Linux Oracle servers the following messages has started
to appear :

Jun 29 07:16:32 blanco kernel: swap_free: Trying to free nonexistent swap-page
Jun 29 07:16:32 blanco kernel: swap_free: Trying to free nonexistent swap-page

They seem to always come in pairs, and usually with about three hours
between them.

The database had to be restored from backup because of massive table
corruption recently, but these messages also appeared before we had to
restore it. (But we believe they might have caused the corruption.)

I also find some of these:

Jun 29 06:25:01 blanco kernel: EXT2-fs error (device sd(8,10)): ext2_readdir: bad entry in directory #172258: rec_len %% 4 != 0 - offset=192, inode=812610409, rec_len=11833, name_len=115
Jun 29 06:25:32 blanco kernel: EXT2-fs error (device sd(8,10)): ext2_readdir: bad entry in directory #172258: rec_len %% 4 != 0 - offset=192, inode=812610409, rec_len=11833, name_len=115

Machine is a 2x933MhZ P3 with 2GB of memory. Kernel version is now
2.2.19, but the same problem appeared with 2.2.18 as well. The
database is in moderate to heavy use 24/7 and with a lot (~ 500 - 3000)
processes during business hours.

The machine has only 128MB of swap, is this to little since it has a
full 2GB of memory?




The kernel is stock 2.2.19 with the following patch applied:

--- include/linux/tasks.h~ Wed Jan 17 14:45:54 2001
+++ include/linux/tasks.h Wed Jan 17 14:46:39 2001
@@ -11,7 +11,7 @@
 #define NR_CPUS 1
 #endif
 
-#define NR_TASKS 512 /* On x86 Max about 4000 */
+#define NR_TASKS 4000 /* On x86 Max about 4000 */
 
 #define MAX_TASKS_PER_USER (NR_TASKS/2)
 #define MIN_TASKS_LEFT_FOR_ROOT 4

--
Regards
Johan Seland
Programmer
Net Fonds ASA

- 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 : Sat Jun 30 2001 - 21:00:21 EST