| Message ID | c2e19e5e-3d3f-d663-af32-13c3374f5def@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ca1ab89cd2d654661f559bd83ad9fc7323cb6c86 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] r8169: improve rtl_tx | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | warning | WARNING: memory barrier without comment |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
Hello: This patch was applied to netdev/net-next.git (refs/heads/master): On Wed, 11 Nov 2020 22:56:29 +0100 you wrote: > We can simplify the for() condition and eliminate variable tx_left. > The change also considers that tp->cur_tx may be incremented by a > racing rtl8169_start_xmit(). > In addition replace the write to tp->dirty_tx and the following > smp_mb() with an equivalent call to smp_store_mb(). This implicitly > adds a WRITE_ONCE() to the write. > > [...] Here is the summary with links: - [net-next] r8169: improve rtl_tx https://git.kernel.org/netdev/net-next/c/ca1ab89cd2d6 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index 641c94a46..8910e900e 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4362,11 +4362,11 @@ static void rtl8169_pcierr_interrupt(struct net_device *dev) static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, int budget) { - unsigned int dirty_tx, tx_left, bytes_compl = 0, pkts_compl = 0; + unsigned int dirty_tx, bytes_compl = 0, pkts_compl = 0; dirty_tx = tp->dirty_tx; - for (tx_left = READ_ONCE(tp->cur_tx) - dirty_tx; tx_left; tx_left--) { + while (READ_ONCE(tp->cur_tx) != dirty_tx) { unsigned int entry = dirty_tx % NUM_TX_DESC; struct sk_buff *skb = tp->tx_skb[entry].skb; u32 status; @@ -4389,7 +4389,6 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, netdev_completed_queue(dev, pkts_compl, bytes_compl); dev_sw_netstats_tx_add(dev, pkts_compl, bytes_compl); - tp->dirty_tx = dirty_tx; /* Sync with rtl8169_start_xmit: * - publish dirty_tx ring index (write barrier) * - refresh cur_tx ring index and queue status (read barrier) @@ -4397,7 +4396,7 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, * a racing xmit thread can only have a right view of the * ring status. */ - smp_mb(); + smp_store_mb(tp->dirty_tx, dirty_tx); if (netif_queue_stopped(dev) && rtl_tx_slots_avail(tp, MAX_SKB_FRAGS)) { netif_wake_queue(dev);
We can simplify the for() condition and eliminate variable tx_left. The change also considers that tp->cur_tx may be incremented by a racing rtl8169_start_xmit(). In addition replace the write to tp->dirty_tx and the following smp_mb() with an equivalent call to smp_store_mb(). This implicitly adds a WRITE_ONCE() to the write. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/net/ethernet/realtek/r8169_main.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)