1. 12 Sep, 2014 32 commits
  2. 03 Sep, 2014 1 commit
  3. 27 Aug, 2014 7 commits
    • Boris Ostrovsky's avatar
      x86/espfix/xen: Fix allocation of pages for paravirt page tables · 5d1b4311
      Boris Ostrovsky authored
      commit 8762e509 upstream.
      
      init_espfix_ap() is currently off by one level when informing hypervisor
      that allocated pages will be used for ministacks' page tables.
      
      The most immediate effect of this on a PV guest is that if
      'stack_page = __get_free_page()' returns a non-zeroed-out page the hypervisor
      will refuse to use it for a page table (which it shouldn't be anyway). This will
      result in warnings by both Xen and Linux.
      
      More importantly, a subsequent write to that page (again, by a PV guest) is
      likely to result in fatal page fault.
      Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      Link: http://lkml.kernel.org/r/1404926298-5565-1-git-send-email-boris.ostrovsky@oracle.comReviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5d1b4311
    • willy tarreau's avatar
      net: mvneta: replace Tx timer with a real interrupt · 10d937e0
      willy tarreau authored
      Right now the mvneta driver doesn't handle Tx IRQ, and relies on two
      mechanisms to flush Tx descriptors : a flush at the end of mvneta_tx()
      and a timer. If a burst of packets is emitted faster than the device
      can send them, then the queue is stopped until next wake-up of the
      timer 10ms later. This causes jerky output traffic with bursts and
      pauses, making it difficult to reach line rate with very few streams.
      
      A test on UDP traffic shows that it's not possible to go beyond 134
      Mbps / 12 kpps of outgoing traffic with 1500-bytes IP packets. Routed
      traffic tends to observe pauses as well if the traffic is bursty,
      making it even burstier after the wake-up.
      
      It seems that this feature was inherited from the original driver but
      nothing there mentions any reason for not using the interrupt instead,
      which the chip supports.
      
      Thus, this patch enables Tx interrupts and removes the timer. It does
      the two at once because it's not really possible to make the two
      mechanisms coexist, so a split patch doesn't make sense.
      
      First tests performed on a Mirabox (Armada 370) show that less CPU
      seems to be used when sending traffic. One reason might be that we now
      call the mvneta_tx_done_gbe() with a mask indicating which queues have
      been done instead of looping over all of them.
      
      The same UDP test above now happily reaches 987 Mbps / 87.7 kpps.
      Single-stream TCP traffic can now more easily reach line rate. HTTP
      transfers of 1 MB objects over a single connection went from 730 to
      840 Mbps. It is even possible to go significantly higher (>900 Mbps)
      by tweaking tcp_tso_win_divisor.
      
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
      Cc: Arnaud Ebalard <arno@natisbad.org>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Tested-by: default avatarArnaud Ebalard <arno@natisbad.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      (cherry picked from commit 71f6d1b3)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      10d937e0
    • willy tarreau's avatar
      net: mvneta: add missing bit descriptions for interrupt masks and causes · 7a399737
      willy tarreau authored
      Marvell has not published the chip's datasheet yet, so it's very hard
      to find the relevant bits to manipulate to change the IRQ behaviour.
      Fortunately, these bits are described in the proprietary LSP patch set
      which is publicly available here :
      
          http://www.plugcomputer.org/downloads/mirabox/
      
      So let's put them back in the driver in order to reduce the burden of
      current and future maintenance.
      
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
      Tested-by: default avatarArnaud Ebalard <arno@natisbad.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      (cherry picked from commit 40ba35e7)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      7a399737
    • willy tarreau's avatar
      net: mvneta: do not schedule in mvneta_tx_timeout · f1b0e3b7
      willy tarreau authored
      If a queue timeout is reported, we can oops because of some
      schedules while the caller is atomic, as shown below :
      
        mvneta d0070000.ethernet eth0: tx timeout
        BUG: scheduling while atomic: bash/1528/0x00000100
        Modules linked in: slhttp_ethdiv(C) [last unloaded: slhttp_ethdiv]
        CPU: 2 PID: 1528 Comm: bash Tainted: G        WC   3.13.0-rc4-mvebu-nf #180
        [<c0011bd9>] (unwind_backtrace+0x1/0x98) from [<c000f1ab>] (show_stack+0xb/0xc)
        [<c000f1ab>] (show_stack+0xb/0xc) from [<c02ad323>] (dump_stack+0x4f/0x64)
        [<c02ad323>] (dump_stack+0x4f/0x64) from [<c02abe67>] (__schedule_bug+0x37/0x4c)
        [<c02abe67>] (__schedule_bug+0x37/0x4c) from [<c02ae261>] (__schedule+0x325/0x3ec)
        [<c02ae261>] (__schedule+0x325/0x3ec) from [<c02adb97>] (schedule_timeout+0xb7/0x118)
        [<c02adb97>] (schedule_timeout+0xb7/0x118) from [<c0020a67>] (msleep+0xf/0x14)
        [<c0020a67>] (msleep+0xf/0x14) from [<c01dcbe5>] (mvneta_stop_dev+0x21/0x194)
        [<c01dcbe5>] (mvneta_stop_dev+0x21/0x194) from [<c01dcfe9>] (mvneta_tx_timeout+0x19/0x24)
        [<c01dcfe9>] (mvneta_tx_timeout+0x19/0x24) from [<c024afc7>] (dev_watchdog+0x18b/0x1c4)
        [<c024afc7>] (dev_watchdog+0x18b/0x1c4) from [<c0020b53>] (call_timer_fn.isra.27+0x17/0x5c)
        [<c0020b53>] (call_timer_fn.isra.27+0x17/0x5c) from [<c0020cad>] (run_timer_softirq+0x115/0x170)
        [<c0020cad>] (run_timer_softirq+0x115/0x170) from [<c001ccb9>] (__do_softirq+0xbd/0x1a8)
        [<c001ccb9>] (__do_softirq+0xbd/0x1a8) from [<c001cfad>] (irq_exit+0x61/0x98)
        [<c001cfad>] (irq_exit+0x61/0x98) from [<c000d4bf>] (handle_IRQ+0x27/0x60)
        [<c000d4bf>] (handle_IRQ+0x27/0x60) from [<c000843b>] (armada_370_xp_handle_irq+0x33/0xc8)
        [<c000843b>] (armada_370_xp_handle_irq+0x33/0xc8) from [<c000fba9>] (__irq_usr+0x49/0x60)
      
      Ben Hutchings attempted to propose a better fix consisting in using a
      scheduled work for this, but while it fixed this panic, it caused other
      random freezes and panics proving that the reset sequence in the driver
      is unreliable and that additional fixes should be investigated.
      
      When sending multiple streams over a link limited to 100 Mbps, Tx timeouts
      happen from time to time, and the driver correctly recovers only when the
      function is disabled.
      
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Tested-by: default avatarArnaud Ebalard <arno@natisbad.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      (cherry picked from commit 29021366)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      f1b0e3b7
    • willy tarreau's avatar
      net: mvneta: use per_cpu stats to fix an SMP lock up · 6a026d8f
      willy tarreau authored
      Stats writers are mvneta_rx() and mvneta_tx(). They don't lock anything
      when they update the stats, and as a result, it randomly happens that
      the stats freeze on SMP if two updates happen during stats retrieval.
      This is very easily reproducible by starting two HTTP servers and binding
      each of them to a different CPU, then consulting /proc/net/dev in loops
      during transfers, the interface should immediately lock up. This issue
      also randomly happens upon link state changes during transfers, because
      the stats are collected in this situation, but it takes more attempts to
      reproduce it.
      
      The comments in netdevice.h suggest using per_cpu stats instead to get
      rid of this issue.
      
      This patch implements this. It merges both rx_stats and tx_stats into
      a single "stats" member with a single syncp. Both mvneta_rx() and
      mvneta_rx() now only update the a single CPU's counters.
      
      In turn, mvneta_get_stats64() does the summing by iterating over all CPUs
      to get their respective stats.
      
      With this change, stats are still correct and no more lockup is encountered.
      
      Note that this bug was present since the first import of the mvneta
      driver.  It might make sense to backport it to some stable trees. If
      so, it depends on "d33dc73 net: mvneta: increase the 64-bit rx/tx stats
      out of the hot path".
      
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Tested-by: default avatarArnaud Ebalard <arno@natisbad.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      (cherry picked from commit 74c41b04)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      6a026d8f
    • willy tarreau's avatar
      net: mvneta: increase the 64-bit rx/tx stats out of the hot path · 7d798913
      willy tarreau authored
      Better count packets and bytes in the stack and on 32 bit then
      accumulate them at the end for once. This saves two memory writes
      and two memory barriers per packet. The incoming packet rate was
      increased by 4.7% on the Openblocks AX3 thanks to this.
      
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Tested-by: default avatarArnaud Ebalard <arno@natisbad.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      (cherry picked from commit dc4277dd)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      7d798913
    • Johannes Berg's avatar
      Revert "mac80211: move "bufferable MMPDU" check to fix AP mode scan" · 9e1bbd3f
      Johannes Berg authored
      This reverts commit 277d916f as it was
      at least breaking iwlwifi by setting the IEEE80211_TX_CTL_NO_PS_BUFFER
      flag in all kinds of interface modes, not only for AP mode where it is
      appropriate.
      
      To avoid reintroducing the original problem, explicitly check for probe
      request frames in the multicast buffering code.
      
      Cc: stable@vger.kernel.org
      Fixes: 277d916f ("mac80211: move "bufferable MMPDU" check to fix AP mode scan")
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      
      (cherry picked from commit 08b99399)
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      9e1bbd3f