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Revert "can: statistics: use atomic access in hot path"

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This reverts commit 4b07ce83e9 which is
commit 80b5f90158d1364cbd80ad82852a757fc0692bf2 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I5458aa41226201953c4c9be42e4c3993293c8b7b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman
2025-04-15 10:01:08 +00:00
parent 522ff9a1db
commit f6e3f07621
3 changed files with 31 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
net/can/af_can.c
View File

@@ -287,8 +287,8 @@ int can_send(struct sk_buff *skb, int loop)
netif_rx(newskb);
/* update statistics */
atomic_long_inc(&pkg_stats->tx_frames);
atomic_long_inc(&pkg_stats->tx_frames_delta);
pkg_stats->tx_frames++;
pkg_stats->tx_frames_delta++;
return 0;
@@ -648,8 +648,8 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
int matches;
/* update statistics */
atomic_long_inc(&pkg_stats->rx_frames);
atomic_long_inc(&pkg_stats->rx_frames_delta);
pkg_stats->rx_frames++;
pkg_stats->rx_frames_delta++;
/* create non-zero unique skb identifier together with *skb */
while (!(can_skb_prv(skb)->skbcnt))
@@ -670,8 +670,8 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
consume_skb(skb);
if (matches > 0) {
atomic_long_inc(&pkg_stats->matches);
atomic_long_inc(&pkg_stats->matches_delta);
pkg_stats->matches++;
pkg_stats->matches_delta++;
}
}

12
net/can/af_can.h
View File

@@ -66,9 +66,9 @@ struct receiver {
struct can_pkg_stats {
unsigned long jiffies_init;
atomic_long_t rx_frames;
atomic_long_t tx_frames;
atomic_long_t matches;
unsigned long rx_frames;
unsigned long tx_frames;
unsigned long matches;
unsigned long total_rx_rate;
unsigned long total_tx_rate;
@@ -82,9 +82,9 @@ struct can_pkg_stats {
unsigned long max_tx_rate;
unsigned long max_rx_match_ratio;
atomic_long_t rx_frames_delta;
atomic_long_t tx_frames_delta;
atomic_long_t matches_delta;
unsigned long rx_frames_delta;
unsigned long tx_frames_delta;
unsigned long matches_delta;
};
/* persistent statistics */

46
net/can/proc.c
View File

@@ -118,13 +118,6 @@ void can_stat_update(struct timer_list *t)
struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
unsigned long j = jiffies; /* snapshot */
long rx_frames = atomic_long_read(&pkg_stats->rx_frames);
long tx_frames = atomic_long_read(&pkg_stats->tx_frames);
long matches = atomic_long_read(&pkg_stats->matches);
long rx_frames_delta = atomic_long_read(&pkg_stats->rx_frames_delta);
long tx_frames_delta = atomic_long_read(&pkg_stats->tx_frames_delta);
long matches_delta = atomic_long_read(&pkg_stats->matches_delta);
/* restart counting in timer context on user request */
if (user_reset)
can_init_stats(net);
@@ -134,33 +127,35 @@ void can_stat_update(struct timer_list *t)
can_init_stats(net);
/* prevent overflow in calc_rate() */
if (rx_frames > (LONG_MAX / HZ))
if (pkg_stats->rx_frames > (ULONG_MAX / HZ))
can_init_stats(net);
/* prevent overflow in calc_rate() */
if (tx_frames > (LONG_MAX / HZ))
if (pkg_stats->tx_frames > (ULONG_MAX / HZ))
can_init_stats(net);
/* matches overflow - very improbable */
if (matches > (LONG_MAX / 100))
if (pkg_stats->matches > (ULONG_MAX / 100))
can_init_stats(net);
/* calc total values */
if (rx_frames)
pkg_stats->total_rx_match_ratio = (matches * 100) / rx_frames;
if (pkg_stats->rx_frames)
pkg_stats->total_rx_match_ratio = (pkg_stats->matches * 100) /
pkg_stats->rx_frames;
pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
tx_frames);
pkg_stats->tx_frames);
pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
rx_frames);
pkg_stats->rx_frames);
/* calc current values */
if (rx_frames_delta)
if (pkg_stats->rx_frames_delta)
pkg_stats->current_rx_match_ratio =
(matches_delta * 100) / rx_frames_delta;
(pkg_stats->matches_delta * 100) /
pkg_stats->rx_frames_delta;
pkg_stats->current_tx_rate = calc_rate(0, HZ, tx_frames_delta);
pkg_stats->current_rx_rate = calc_rate(0, HZ, rx_frames_delta);
pkg_stats->current_tx_rate = calc_rate(0, HZ, pkg_stats->tx_frames_delta);
pkg_stats->current_rx_rate = calc_rate(0, HZ, pkg_stats->rx_frames_delta);
/* check / update maximum values */
if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
@@ -173,9 +168,9 @@ void can_stat_update(struct timer_list *t)
pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
/* clear values for 'current rate' calculation */
atomic_long_set(&pkg_stats->tx_frames_delta, 0);
atomic_long_set(&pkg_stats->rx_frames_delta, 0);
atomic_long_set(&pkg_stats->matches_delta, 0);
pkg_stats->tx_frames_delta = 0;
pkg_stats->rx_frames_delta = 0;
pkg_stats->matches_delta = 0;
/* restart timer (one second) */
mod_timer(&net->can.stattimer, round_jiffies(jiffies + HZ));
@@ -219,12 +214,9 @@ static int can_stats_proc_show(struct seq_file *m, void *v)
struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
seq_putc(m, '\n');
seq_printf(m, " %8ld transmitted frames (TXF)\n",
atomic_long_read(&pkg_stats->tx_frames));
seq_printf(m, " %8ld received frames (RXF)\n",
atomic_long_read(&pkg_stats->rx_frames));
seq_printf(m, " %8ld matched frames (RXMF)\n",
atomic_long_read(&pkg_stats->matches));
seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
seq_putc(m, '\n');