rfs: better sizing of dev_flow_table
Aim of this patch is to provide full range of rps_flow_cnt on 64bit arches.
Theorical limit on number of flows is 2^32
Fix some buggy RPS/RFS macros as well.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
CC: Xi Wang <xi.wang@gmail.com>
CC: Laurent Chavey <chavey@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 4b4d0b0..abf4393 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -622,15 +622,15 @@
char *buf)
{
struct rps_dev_flow_table *flow_table;
- unsigned int val = 0;
+ unsigned long val = 0;
rcu_read_lock();
flow_table = rcu_dereference(queue->rps_flow_table);
if (flow_table)
- val = flow_table->mask + 1;
+ val = (unsigned long)flow_table->mask + 1;
rcu_read_unlock();
- return sprintf(buf, "%u\n", val);
+ return sprintf(buf, "%lu\n", val);
}
static void rps_dev_flow_table_release_work(struct work_struct *work)
@@ -654,36 +654,46 @@
struct rx_queue_attribute *attr,
const char *buf, size_t len)
{
- unsigned int count;
- char *endp;
+ unsigned long mask, count;
struct rps_dev_flow_table *table, *old_table;
static DEFINE_SPINLOCK(rps_dev_flow_lock);
+ int rc;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
- count = simple_strtoul(buf, &endp, 0);
- if (endp == buf)
- return -EINVAL;
+ rc = kstrtoul(buf, 0, &count);
+ if (rc < 0)
+ return rc;
if (count) {
- int i;
-
- if (count > INT_MAX)
+ mask = count - 1;
+ /* mask = roundup_pow_of_two(count) - 1;
+ * without overflows...
+ */
+ while ((mask | (mask >> 1)) != mask)
+ mask |= (mask >> 1);
+ /* On 64 bit arches, must check mask fits in table->mask (u32),
+ * and on 32bit arches, must check RPS_DEV_FLOW_TABLE_SIZE(mask + 1)
+ * doesnt overflow.
+ */
+#if BITS_PER_LONG > 32
+ if (mask > (unsigned long)(u32)mask)
return -EINVAL;
- count = roundup_pow_of_two(count);
- if (count > (ULONG_MAX - sizeof(struct rps_dev_flow_table))
+#else
+ if (mask > (ULONG_MAX - RPS_DEV_FLOW_TABLE_SIZE(1))
/ sizeof(struct rps_dev_flow)) {
/* Enforce a limit to prevent overflow */
return -EINVAL;
}
- table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));
+#endif
+ table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(mask + 1));
if (!table)
return -ENOMEM;
- table->mask = count - 1;
- for (i = 0; i < count; i++)
- table->flows[i].cpu = RPS_NO_CPU;
+ table->mask = mask;
+ for (count = 0; count <= mask; count++)
+ table->flows[count].cpu = RPS_NO_CPU;
} else
table = NULL;