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* [net-next PATCH v3 2/3] sysctl: add proc_dobitmap
@ 2010-02-11  2:53 Octavian Purdila
  0 siblings, 0 replies; 2+ messages in thread
From: Octavian Purdila @ 2010-02-11  2:53 UTC (permalink / raw)
  To: netdev

The new function can be used to update bitmaps via /proc. Bits can be
set by writing positive values in the file and cleared by writing
negative values (e.g. 0 2 will set bits 1 and 3, -0 -2 will clear
them). Reading will show only the set bits.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Cc: WANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
---
 include/linux/sysctl.h |    2 +
 kernel/sysctl.c        |   76 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 0 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 9f236cd..ba89bf2 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -985,6 +985,8 @@ extern int proc_doulongvec_minmax(struct ctl_table *, int,
 				  void __user *, size_t *, loff_t *);
 extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int,
 				      void __user *, size_t *, loff_t *);
+extern int proc_dobitmap(struct ctl_table *, int,
+			 void __user *, size_t *, loff_t *);
 
 /*
  * Register a set of sysctl names by calling register_sysctl_table
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b0f9618..b8959f4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2596,6 +2596,82 @@ static int proc_do_cad_pid(struct ctl_table *table, int write,
 	return 0;
 }
 
+/**
+ * proc_dobitmap - read/write from/to a bitmap
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ * @ppos: the current position in the file
+ *
+ * The bitmap is stored at table->data and the bitmap length (in bits)
+ * in table->maxlen. Reading from the proc file will show the set bits.
+ * Writing positive values sets the bits, negative values clears them
+ * (e.g. 0 2 sets the first and 3rd bit, -0 -2 clears them).
+ *
+ * Returns 0 on success.
+ */
+int proc_dobitmap(struct ctl_table *table, int write,
+		  void __user *_buffer, size_t *lenp, loff_t *ppos)
+{
+	bool first = 1;
+	unsigned long *bitmap = (unsigned long *) table->data;
+	unsigned long bitmap_len = table->maxlen;
+	int left = *lenp, err = 0;
+	char __user *buffer = (char __user *) _buffer;
+
+	if (!bitmap_len || !left || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		while (left) {
+			unsigned long val;
+			bool neg;
+
+			err = proc_get_next_ulong(&buffer, &left, &val, &neg);
+			if (err)
+				break;
+			if (val >= bitmap_len) {
+				err = -EINVAL;
+				break;
+			}
+			if (neg)
+				clear_bit(val, bitmap);
+			else
+				set_bit(val, bitmap);
+			first = 0;
+		}
+		if (!err)
+			err = proc_skip_wspace(&buffer, &left);
+	} else {
+		unsigned long bit = 0;
+
+		while (left) {
+			bit = find_next_bit(bitmap, bitmap_len, bit);
+			if (bit >= bitmap_len)
+				break;
+			err = proc_put_ulong(&buffer, &left, bit, 0, first);
+			if (err)
+				break;
+			first = 0; bit++;
+		}
+		if (!err)
+			err = proc_put_newline(&buffer, &left);
+	}
+
+	if (first && write && !err)
+		err = -EINVAL;
+	if (err == -EFAULT /* do we really need to check for -EFAULT? */ ||
+	    (write && first))
+		return err ? : -EINVAL;
+	*lenp -= left;
+	*ppos += *lenp;
+	return 0;
+}
+
 #else /* CONFIG_PROC_FS */
 
 int proc_dostring(struct ctl_table *table, int write,
-- 
1.5.6.5


^ permalink raw reply related	[flat|nested] 2+ messages in thread
* [net-next PATCH v3 0/3] net: reserve ports for applications using fixed port numbers
@ 2010-02-11  2:09 Octavian Purdila
  2010-02-11  2:09 ` [net-next PATCH v3 2/3] sysctl: add proc_dobitmap Octavian Purdila
  0 siblings, 1 reply; 2+ messages in thread
From: Octavian Purdila @ 2010-02-11  2:09 UTC (permalink / raw)
  To: David Miller
  Cc: Octavian Purdila, netdev, linux-kernel, WANG Cong, Neil Horman,
	Eric Dumazet


This patch series is based on Amerigo's v2 but it now uses a bitmap
for port reservation.

I've ran a while (1) { bind(0) } test (with ip_local_port_range
1024 65000) to see if there is any performance difference between the
two approaches (ranges vs bitmap). I could not detect any significant
difference, both cases scored in 2.76s +/- 0.01 on my setup.

I've based this patch series on current net-next, but it contains a
significant non networking part. Please let me know if I should handle
this differently.

Octavian Purdila (3):
  sysctl: refactor integer handling proc code
  sysctl: add proc_dobitmap
  net: reserve ports for applications using fixed port numbers

 Documentation/networking/ip-sysctl.txt |   12 +
 drivers/infiniband/core/cma.c          |    7 +-
 include/linux/sysctl.h                 |    2 +
 include/net/ip.h                       |    6 +
 kernel/sysctl.c                        |  374 +++++++++++++++++++-------------
 net/ipv4/inet_connection_sock.c        |    5 +
 net/ipv4/inet_hashtables.c             |    2 +
 net/ipv4/sysctl_net_ipv4.c             |    7 +
 net/ipv4/udp.c                         |    3 +-
 net/sctp/socket.c                      |    2 +
 10 files changed, 264 insertions(+), 156 deletions(-)

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2010-02-11  3:00 UTC | newest]

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