| Message ID | 23c0ff1feddcc690ee66adebefdc3b10031afe1b.1576007149.git.Jose.Abreu@synopsys.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net: stmmac: Improvements for -next | expand |
On Tue, 10 Dec 2019 20:54:44 +0100, Jose Abreu wrote: > When we have pending packets we re-arm the TX timer with a magic value. > Change this from the hardcoded value to the pre-defined TX coalesce > timer value. s/pre-defined/user controlled/ ? > Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com> > --- > Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> > Cc: Alexandre Torgue <alexandre.torgue@st.com> > Cc: Jose Abreu <joabreu@synopsys.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > Cc: netdev@vger.kernel.org > Cc: linux-stm32@st-md-mailman.stormreply.com > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index f61780ae30ac..726a17d9cc35 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -1975,7 +1975,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) > > /* We still have pending packets, let's call for a new scheduling */ > if (tx_q->dirty_tx != tx_q->cur_tx) > - mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10)); > + mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer)); I think intent of this code is to re-check the ring soon. The same value of 10 is used in stmmac_tx_timer() for quick re-check. tx_coal_timer defaults to 1000, so it's quite a jump from 10 to 1000. I think the commit message leaves too much unsaid. Also if you want to change to the ethtool timeout value, could you move stmmac_tx_timer_arm() and reuse that helper? > > __netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue)); >
From: Jakub Kicinski <jakub.kicinski@netronome.com> Date: Dec/14/2019, 20:28:37 (UTC+00:00) > On Tue, 10 Dec 2019 20:54:44 +0100, Jose Abreu wrote: > > When we have pending packets we re-arm the TX timer with a magic value. > > Change this from the hardcoded value to the pre-defined TX coalesce > > timer value. > > s/pre-defined/user controlled/ ? > > > Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com> > > --- > > Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> > > Cc: Alexandre Torgue <alexandre.torgue@st.com> > > Cc: Jose Abreu <joabreu@synopsys.com> > > Cc: "David S. Miller" <davem@davemloft.net> > > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > > Cc: netdev@vger.kernel.org > > Cc: linux-stm32@st-md-mailman.stormreply.com > > Cc: linux-arm-kernel@lists.infradead.org > > Cc: linux-kernel@vger.kernel.org > > --- > > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > index f61780ae30ac..726a17d9cc35 100644 > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > @@ -1975,7 +1975,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) > > > > /* We still have pending packets, let's call for a new scheduling */ > > if (tx_q->dirty_tx != tx_q->cur_tx) > > - mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10)); > > + mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer)); > > I think intent of this code is to re-check the ring soon. The same > value of 10 is used in stmmac_tx_timer() for quick re-check. > > tx_coal_timer defaults to 1000, so it's quite a jump from 10 to 1000. > > I think the commit message leaves too much unsaid. > > Also if you want to change to the ethtool timeout value, could you move > stmmac_tx_timer_arm() and reuse that helper? Yeah, it's a quick re-check but 10us can be too low on some speeds and leads to CPU useless-looping. The intent is to let this always be configurable by user. --- Thanks, Jose Miguel Abreu
On Mon, 16 Dec 2019 09:20:53 +0000, Jose Abreu wrote: > > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > > index f61780ae30ac..726a17d9cc35 100644 > > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > > > @@ -1975,7 +1975,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) > > > > > > /* We still have pending packets, let's call for a new scheduling */ > > > if (tx_q->dirty_tx != tx_q->cur_tx) > > > - mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10)); > > > + mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer)); > > > > I think intent of this code is to re-check the ring soon. The same > > value of 10 is used in stmmac_tx_timer() for quick re-check. > > > > tx_coal_timer defaults to 1000, so it's quite a jump from 10 to 1000. > > > > I think the commit message leaves too much unsaid. > > > > Also if you want to change to the ethtool timeout value, could you move > > stmmac_tx_timer_arm() and reuse that helper? > > Yeah, it's a quick re-check but 10us can be too low on some speeds and > leads to CPU useless-looping. The intent is to let this always be > configurable by user. Okay, please do mention the bump from 10us to the default of 1ms in the commit message, though.
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index f61780ae30ac..726a17d9cc35 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1975,7 +1975,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) /* We still have pending packets, let's call for a new scheduling */ if (tx_q->dirty_tx != tx_q->cur_tx) - mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10)); + mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer)); __netif_tx_unlock_bh(netdev_get_tx_queue(priv->dev, queue));
When we have pending packets we re-arm the TX timer with a magic value. Change this from the hardcoded value to the pre-defined TX coalesce timer value. Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com> --- Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Jose Abreu <joabreu@synopsys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)