Followings are our kernel variables' default:
- sb_max: 256K
- tcbhash_size: 128
- udbhash_size: 128
These variables are sometime too small for busy server or gateway.
I'd like to modify config(8) to customize these variables without
recompiling the kernel.
Comment or ok?
Index: usr.sbin/config/cmd.c
===================================================================
RCS file: /disk/cvs/openbsd/src/usr.sbin/config/cmd.c,v
retrieving revision 1.20
diff -u -p -r1.20 cmd.c
--- usr.sbin/config/cmd.c 23 Nov 2013 17:38:15 -0000 1.20
+++ usr.sbin/config/cmd.c 16 Jun 2014 12:25:59 -0000
@@ -24,7 +24,7 @@
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-#include <sys/types.h>
+#include <sys/param.h>
#include <sys/device.h>
#include <sys/time.h>
@@ -61,6 +61,11 @@ cmd_table_t cmd_table[] = {
{"bufcachepercent", Xbufcachepct, "[number]",
"Show/change BUFCACHEPERCENT"},
{"nkmempg", Xnkmempg, "[number]", "Show/change NKMEMPAGES"},
+ {"sb_max", Xsb_max, "[number]", "Show/change sb_max"},
+ {"udbhashsize", Xudbhashsize, "[number]",
+ "Show/change udbhashsize"},
+ {"tcbhashsize", Xtcbhashsize, "[number]",
+ "Show/change tcbhashsize"},
{NULL, NULL, NULL, NULL}
};
@@ -313,5 +318,58 @@ int
Xnkmempg(cmd_t *cmd)
{
int_variable_adjust(cmd, I_NKMEMPG, "nkmempages");
+ return (CMD_CONT);
+}
+
+int
+Xsb_max(cmd_t *cmd)
+{
+ int_variable_adjust(cmd, I_SB_MAX, "sb_max");
+ return (CMD_CONT);
+}
+
+void
+pow2_variable_adjust(const cmd_t *cmd, int idx, const char *name)
+{
+ int i, *v, num;
+
+ if (nl[idx].n_type != 0) {
+ ukc_mod_kernel = 1;
+
+ v = (int *)adjust((caddr_t)(nl[idx].n_value));
+
+ if (strlen(cmd->args) == 0) {
+ printf("%s = %d\n", name, *v);
+ } else {
+ if (number(cmd->args, &num) == 0) {
+ if (!powerof2(num)) {
+ for (i = 0; num; num = num >> 1)
+ i++;
+ num = 1 << i;
+ printf("Warning: number must be "
+ "power of 2. Rounded up to %d\n",
+ num);
+ }
+ *v = num;
+ printf("%s = %d\n", name, num);
+ } else
+ printf("Unknown argument\n");
+ }
+ } else
+ printf("This kernel does not support modification of %s.\n",
+ name);
+}
+
+int
+Xudbhashsize(cmd_t *cmd)
+{
+ pow2_variable_adjust(cmd, I_UDBHASHSIZE, "udbhashsize");
+ return (CMD_CONT);
+}
+
+int
+Xtcbhashsize(cmd_t *cmd)
+{
+ pow2_variable_adjust(cmd, I_TCBHASHSIZE, "tcbhashsize");
return (CMD_CONT);
}
Index: usr.sbin/config/cmd.h
===================================================================
RCS file: /disk/cvs/openbsd/src/usr.sbin/config/cmd.h,v
retrieving revision 1.7
diff -u -p -r1.7 cmd.h
--- usr.sbin/config/cmd.h 3 Jun 2003 00:52:35 -0000 1.7
+++ usr.sbin/config/cmd.h 16 Jun 2014 11:58:37 -0000
@@ -72,6 +72,9 @@ int Xbufcachepct(cmd_t *);
int Xnkmempg(cmd_t *);
int Xshmseg(cmd_t *);
int Xshmmaxpgs(cmd_t *);
+int Xsb_max(cmd_t *);
+int Xudbhashsize(cmd_t *);
+int Xtcbhashsize(cmd_t *);
#endif /* _CMD_H */
Index: usr.sbin/config/config.8
===================================================================
RCS file: /disk/cvs/openbsd/src/usr.sbin/config/config.8,v
retrieving revision 1.60
diff -u -p -r1.60 config.8
--- usr.sbin/config/config.8 20 Jan 2014 01:11:49 -0000 1.60
+++ usr.sbin/config/config.8 16 Jun 2014 11:58:37 -0000
@@ -321,6 +321,21 @@ is the number of minutes west of GMT and
.Va dst
is non-zero if Daylight Saving Time is in effect.
Without arguments, displays its current value.
+.It Ic sb_max Op Ar number
+Change the sb_max value.
+Without arguments, displays its current value.
+.It Ic tcbhashsize Op Ar number
+Change the tcbhashsize value.
+Without arguments, displays its current value.
+The
+.Ar number
+should be power of 2, otherwise it will be rounded up forcibly.
+.It Ic udbhashsize Op Ar number
+Change the tcbhashsize value.
+Without arguments, displays its current value.
+The
+.Ar number
+should be power of 2, otherwise it will be rounded up forcibly.
.El
.Sh EXAMPLES (kernel building)
Note:
Index: usr.sbin/config/ukc.h
===================================================================
RCS file: /disk/cvs/openbsd/src/usr.sbin/config/ukc.h,v
retrieving revision 1.12
diff -u -p -r1.12 ukc.h
--- usr.sbin/config/ukc.h 10 Dec 2009 22:07:19 -0000 1.12
+++ usr.sbin/config/ukc.h 16 Jun 2014 11:58:37 -0000
@@ -48,7 +48,10 @@
#define I_NMBCLUSTERS 18
#define I_BUFCACHEPCT 19
#define I_NKMEMPG 20
-#define NLENTRIES 21
+#define I_SB_MAX 21
+#define I_UDBHASHSIZE 22
+#define I_TCBHASHSIZE 23
+#define NLENTRIES 24
#ifdef UKC_MAIN
struct nlist nl[] = {
@@ -73,6 +76,9 @@ struct nlist nl[] = {
{ "_nmbclust" },
{ "_bufcachepercent" },
{ "_nkmempages" },
+ { "_sb_max" },
+ { "_udbhashsize" },
+ { "_tcbhashsize" },
{ NULL },
};
struct nlist knl[] = {
@@ -97,6 +103,9 @@ struct nlist knl[] = {
{ "_nmbclust" },
{ "_bufcachepercent" },
{ "_nkmempages" },
+ { "_sbmax" },
+ { "_udbhashsize" },
+ { "_tcbhashsize" },
{ NULL },
};
int maxdev = 0;
