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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 17:22:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 17:22:09 -0800
commit9753dfe19a85e7e45a34a56f4cb2048bb4f50e27 (patch)
treec017a1b4a70b8447c71b01d8b320e071546b5c9d /lib
parentedf7c8148ec40c0fd27c0ef3f688defcc65e3913 (diff)
parent9f42f126154786e6e76df513004800c8c633f020 (diff)
downloadlinux-9753dfe19a85e7e45a34a56f4cb2048bb4f50e27.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1958 commits) net: pack skb_shared_info more efficiently net_sched: red: split red_parms into parms and vars net_sched: sfq: extend limits cnic: Improve error recovery on bnx2x devices cnic: Re-init dev->stats_addr after chip reset net_sched: Bug in netem reordering bna: fix sparse warnings/errors bna: make ethtool_ops and strings const xgmac: cleanups net: make ethtool_ops const vmxnet3" make ethtool ops const xen-netback: make ops structs const virtio_net: Pass gfp flags when allocating rx buffers. ixgbe: FCoE: Add support for ndo_get_fcoe_hbainfo() call netdev: FCoE: Add new ndo_get_fcoe_hbainfo() call igb: reset PHY after recovering from PHY power down igb: add basic runtime PM support igb: Add support for byte queue limits. e1000: cleanup CE4100 MDIO registers access e1000: unmap ce4100_gbe_mdio_base_virt in e1000_remove ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/dynamic_queue_limits.c133
-rw-r--r--lib/reciprocal_div.c2
-rw-r--r--lib/vsprintf.c19
5 files changed, 159 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 32f3e5ae2be..63b5782732e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -244,6 +244,9 @@ config CPU_RMAP
bool
depends on SMP
+config DQL
+ bool
+
#
# Netlink attribute parsing support is select'ed if needed
#
diff --git a/lib/Makefile b/lib/Makefile
index a4da283f5dc..ff00d4dcb7e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -115,6 +115,8 @@ obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
obj-$(CONFIG_CORDIC) += cordic.o
+obj-$(CONFIG_DQL) += dynamic_queue_limits.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h
diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
new file mode 100644
index 00000000000..3d1bdcdd7db
--- /dev/null
+++ b/lib/dynamic_queue_limits.c
@@ -0,0 +1,133 @@
+/*
+ * Dynamic byte queue limits. See include/linux/dynamic_queue_limits.h
+ *
+ * Copyright (c) 2011, Tom Herbert <therbert@google.com>
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/kernel.h>
+#include <linux/dynamic_queue_limits.h>
+
+#define POSDIFF(A, B) ((A) > (B) ? (A) - (B) : 0)
+
+/* Records completed count and recalculates the queue limit */
+void dql_completed(struct dql *dql, unsigned int count)
+{
+ unsigned int inprogress, prev_inprogress, limit;
+ unsigned int ovlimit, all_prev_completed, completed;
+
+ /* Can't complete more than what's in queue */
+ BUG_ON(count > dql->num_queued - dql->num_completed);
+
+ completed = dql->num_completed + count;
+ limit = dql->limit;
+ ovlimit = POSDIFF(dql->num_queued - dql->num_completed, limit);
+ inprogress = dql->num_queued - completed;
+ prev_inprogress = dql->prev_num_queued - dql->num_completed;
+ all_prev_completed = POSDIFF(completed, dql->prev_num_queued);
+
+ if ((ovlimit && !inprogress) ||
+ (dql->prev_ovlimit && all_prev_completed)) {
+ /*
+ * Queue considered starved if:
+ * - The queue was over-limit in the last interval,
+ * and there is no more data in the queue.
+ * OR
+ * - The queue was over-limit in the previous interval and
+ * when enqueuing it was possible that all queued data
+ * had been consumed. This covers the case when queue
+ * may have becomes starved between completion processing
+ * running and next time enqueue was scheduled.
+ *
+ * When queue is starved increase the limit by the amount
+ * of bytes both sent and completed in the last interval,
+ * plus any previous over-limit.
+ */
+ limit += POSDIFF(completed, dql->prev_num_queued) +
+ dql->prev_ovlimit;
+ dql->slack_start_time = jiffies;
+ dql->lowest_slack = UINT_MAX;
+ } else if (inprogress && prev_inprogress && !all_prev_completed) {
+ /*
+ * Queue was not starved, check if the limit can be decreased.
+ * A decrease is only considered if the queue has been busy in
+ * the whole interval (the check above).
+ *
+ * If there is slack, the amount of execess data queued above
+ * the the amount needed to prevent starvation, the queue limit
+ * can be decreased. To avoid hysteresis we consider the
+ * minimum amount of slack found over several iterations of the
+ * completion routine.
+ */
+ unsigned int slack, slack_last_objs;
+
+ /*
+ * Slack is the maximum of
+ * - The queue limit plus previous over-limit minus twice
+ * the number of objects completed. Note that two times
+ * number of completed bytes is a basis for an upper bound
+ * of the limit.
+ * - Portion of objects in the last queuing operation that
+ * was not part of non-zero previous over-limit. That is
+ * "round down" by non-overlimit portion of the last
+ * queueing operation.
+ */
+ slack = POSDIFF(limit + dql->prev_ovlimit,
+ 2 * (completed - dql->num_completed));
+ slack_last_objs = dql->prev_ovlimit ?
+ POSDIFF(dql->prev_last_obj_cnt, dql->prev_ovlimit) : 0;
+
+ slack = max(slack, slack_last_objs);
+
+ if (slack < dql->lowest_slack)
+ dql->lowest_slack = slack;
+
+ if (time_after(jiffies,
+ dql->slack_start_time + dql->slack_hold_time)) {
+ limit = POSDIFF(limit, dql->lowest_slack);
+ dql->slack_start_time = jiffies;
+ dql->lowest_slack = UINT_MAX;
+ }
+ }
+
+ /* Enforce bounds on limit */
+ limit = clamp(limit, dql->min_limit, dql->max_limit);
+
+ if (limit != dql->limit) {
+ dql->limit = limit;
+ ovlimit = 0;
+ }
+
+ dql->adj_limit = limit + completed;
+ dql->prev_ovlimit = ovlimit;
+ dql->prev_last_obj_cnt = dql->last_obj_cnt;
+ dql->num_completed = completed;
+ dql->prev_num_queued = dql->num_queued;
+}
+EXPORT_SYMBOL(dql_completed);
+
+void dql_reset(struct dql *dql)
+{
+ /* Reset all dynamic values */
+ dql->limit = 0;
+ dql->num_queued = 0;
+ dql->num_completed = 0;
+ dql->last_obj_cnt = 0;
+ dql->prev_num_queued = 0;
+ dql->prev_last_obj_cnt = 0;
+ dql->prev_ovlimit = 0;
+ dql->lowest_slack = UINT_MAX;
+ dql->slack_start_time = jiffies;
+}
+EXPORT_SYMBOL(dql_reset);
+
+int dql_init(struct dql *dql, unsigned hold_time)
+{
+ dql->max_limit = DQL_MAX_LIMIT;
+ dql->min_limit = 0;
+ dql->slack_hold_time = hold_time;
+ dql_reset(dql);
+ return 0;
+}
+EXPORT_SYMBOL(dql_init);
diff --git a/lib/reciprocal_div.c b/lib/reciprocal_div.c
index 6a3bd48fa2a..75510e94f7d 100644
--- a/lib/reciprocal_div.c
+++ b/lib/reciprocal_div.c
@@ -1,5 +1,6 @@
#include <asm/div64.h>
#include <linux/reciprocal_div.h>
+#include <linux/export.h>
u32 reciprocal_value(u32 k)
{
@@ -7,3 +8,4 @@ u32 reciprocal_value(u32 k)
do_div(val, k);
return (u32)val;
}
+EXPORT_SYMBOL(reciprocal_value);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 993599e66e5..8e75003d62f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -777,6 +777,18 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
return string(buf, end, uuid, spec);
}
+static
+char *netdev_feature_string(char *buf, char *end, const u8 *addr,
+ struct printf_spec spec)
+{
+ spec.flags |= SPECIAL | SMALL | ZEROPAD;
+ if (spec.field_width == -1)
+ spec.field_width = 2 + 2 * sizeof(netdev_features_t);
+ spec.base = 16;
+
+ return number(buf, end, *(const netdev_features_t *)addr, spec);
+}
+
int kptr_restrict __read_mostly;
/*
@@ -824,6 +836,7 @@ int kptr_restrict __read_mostly;
* Do not use this feature without some mechanism to verify the
* correctness of the format string and va_list arguments.
* - 'K' For a kernel pointer that should be hidden from unprivileged users
+ * - 'NF' For a netdev_features_t
*
* Note: The difference between 'S' and 'F' is that on ia64 and ppc64
* function pointers are really function descriptors, which contain a
@@ -896,6 +909,12 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
has_capability_noaudit(current, CAP_SYSLOG))))
ptr = NULL;
break;
+ case 'N':
+ switch (fmt[1]) {
+ case 'F':
+ return netdev_feature_string(buf, end, ptr, spec);
+ }
+ break;
}
spec.flags |= SMALL;
if (spec.field_width == -1) {