1. 17 2月, 2016 1 次提交
    • K
      ethtool: correctly ensure {GS}CHANNELS doesn't conflict with GS{RXFH} · d4ab4286
      Keller, Jacob E 提交于
      Ethernet drivers implementing both {GS}RXFH and {GS}CHANNELS ethtool ops
      incorrectly allow SCHANNELS when it would conflict with the settings
      from SRXFH. This occurs because it is not possible for drivers to
      understand whether their Rx flow indirection table has been configured
      or is in the default state. In addition, drivers currently behave in
      various ways when increasing the number of Rx channels.
      
      Some drivers will always destroy the Rx flow indirection table when this
      occurs, whether it has been set by the user or not. Other drivers will
      attempt to preserve the table even if the user has never modified it
      from the default driver settings. Neither of these situation is
      desirable because it leads to unexpected behavior or loss of user
      configuration.
      
      The correct behavior is to simply return -EINVAL when SCHANNELS would
      conflict with the current Rx flow table settings. However, it should
      only do so if the current settings were modified by the user. If we
      required that the new settings never conflict with the current (default)
      Rx flow settings, we would force users to first reduce their Rx flow
      settings and then reduce the number of Rx channels.
      
      This patch proposes a solution implemented in net/core/ethtool.c which
      ensures that all drivers behave correctly. It checks whether the RXFH
      table has been configured to non-default settings, and stores this
      information in a private netdev flag. When the number of channels is
      requested to change, it first ensures that the current Rx flow table is
      not going to assign flows to now disabled channels.
      Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d4ab4286
  2. 12 2月, 2016 4 次提交
  3. 11 2月, 2016 9 次提交
  4. 08 2月, 2016 1 次提交
    • Y
      tcp: new delivery accounting · ddf1af6f
      Yuchung Cheng 提交于
      This patch changes the accounting of how many packets are
      newly acked or sacked when the sender receives an ACK.
      
      The current approach basically computes
      
         newly_acked_sacked = (prior_packets - prior_sacked) -
                              (tp->packets_out - tp->sacked_out)
      
         where prior_packets and prior_sacked out are snapshot
         at the beginning of the ACK processing.
      
      The new approach tracks the delivery information via a new
      TCP state variable "delivered" which monotically increases
      as new packets are delivered in order or out-of-order.
      
      The reason for this change is that the current approach is
      brittle that produces negative or inaccurate estimate.
      
         1) For non-SACK connections, an ACK that advances the SND.UNA
         could reset the DUPACK counters (tp->sacked_out) in
         tcp_process_loss() or tcp_fastretrans_alert(). This inflates
         the inflight suddenly and causes under-estimate or even
         negative estimate. Here is a real example:
      
                         before   after (processing ACK)
         packets_out     75       73
         sacked_out      23        0
         ca state        Loss     Open
      
         The old approach computes (75-23) - (73 - 0) = -21 delivered
         while the new approach computes 1 delivered since it
         considers the 2nd-24th packets are delivered OOO.
      
         2) MSS change would re-count packets_out and sacked_out so
         the estimate is in-accurate and can even become negative.
         E.g., the inflight is doubled when MSS is halved.
      
         3) Spurious retransmission signaled by DSACK is not accounted
      
      The new approach is simpler and more robust. For SACK connections,
      tp->delivered increments as packets are being acked or sacked in
      SACK and ACK processing.
      
      For non-sack connections, it's done in tcp_remove_reno_sacks() and
      tcp_add_reno_sack(). When an ACK advances the SND.UNA, tp->delivered
      is incremented by the number of packets ACKed (less the current
      number of DUPACKs received plus one packet hole).  Upon receiving
      a DUPACK, tp->delivered is incremented assuming one out-of-order
      packet is delivered.
      
      Upon receiving a DSACK, tp->delivered is incremtened assuming one
      retransmission is delivered in tcp_sacktag_write_queue().
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <ncardwell@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ddf1af6f
  5. 06 2月, 2016 5 次提交
  6. 01 2月, 2016 1 次提交
  7. 31 1月, 2016 3 次提交
    • D
      block: use DAX for partition table reads · d1a5f2b4
      Dan Williams 提交于
      Avoid populating pagecache when the block device is in DAX mode.
      Otherwise these page cache entries collide with the fsync/msync
      implementation and break data durability guarantees.
      
      Cc: Jan Kara <jack@suse.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Reported-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Tested-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      d1a5f2b4
    • D
      block: revert runtime dax control of the raw block device · 9f4736fe
      Dan Williams 提交于
      Dynamically enabling DAX requires that the page cache first be flushed
      and invalidated.  This must occur atomically with the change of DAX mode
      otherwise we confuse the fsync/msync tracking and violate data
      durability guarantees.  Eliminate the possibilty of DAX-disabled to
      DAX-enabled transitions for now and revisit this for the next cycle.
      
      Cc: Jan Kara <jack@suse.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      9f4736fe
    • D
      fs, block: force direct-I/O for dax-enabled block devices · 65f87ee7
      Dan Williams 提交于
      Similar to the file I/O path, re-direct all I/O to the DAX path for I/O
      to a block-device special file.  Both regular files and device special
      files can use the common filp->f_mapping->host lookup to determing is
      DAX is enabled.
      
      Otherwise, we confuse the DAX code that does not expect to find live
      data in the page cache:
      
          ------------[ cut here ]------------
          WARNING: CPU: 0 PID: 7676 at mm/filemap.c:217
          __delete_from_page_cache+0x9f6/0xb60()
          Modules linked in:
          CPU: 0 PID: 7676 Comm: a.out Not tainted 4.4.0+ #276
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
           00000000ffffffff ffff88006d3f7738 ffffffff82999e2d 0000000000000000
           ffff8800620a0000 ffffffff86473d20 ffff88006d3f7778 ffffffff81352089
           ffffffff81658d36 ffffffff86473d20 00000000000000d9 ffffea0000009d60
          Call Trace:
           [<     inline     >] __dump_stack lib/dump_stack.c:15
           [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
           [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
           [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
           [<ffffffff81658d36>] __delete_from_page_cache+0x9f6/0xb60 mm/filemap.c:217
           [<ffffffff81658fb2>] delete_from_page_cache+0x112/0x200 mm/filemap.c:244
           [<ffffffff818af369>] __dax_fault+0x859/0x1800 fs/dax.c:487
           [<ffffffff8186f4f6>] blkdev_dax_fault+0x26/0x30 fs/block_dev.c:1730
           [<     inline     >] wp_pfn_shared mm/memory.c:2208
           [<ffffffff816e9145>] do_wp_page+0xc85/0x14f0 mm/memory.c:2307
           [<     inline     >] handle_pte_fault mm/memory.c:3323
           [<     inline     >] __handle_mm_fault mm/memory.c:3417
           [<ffffffff816ecec3>] handle_mm_fault+0x2483/0x4640 mm/memory.c:3446
           [<ffffffff8127eff6>] __do_page_fault+0x376/0x960 arch/x86/mm/fault.c:1238
           [<ffffffff8127f738>] trace_do_page_fault+0xe8/0x420 arch/x86/mm/fault.c:1331
           [<ffffffff812705c4>] do_async_page_fault+0x14/0xd0 arch/x86/kernel/kvm.c:264
           [<ffffffff86338f78>] async_page_fault+0x28/0x30 arch/x86/entry/entry_64.S:986
           [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
          arch/x86/entry/entry_64.S:185
          ---[ end trace dae21e0f85f1f98c ]---
      
      Fixes: 5a023cdb ("block: enable dax for raw block devices")
      Reported-by: NDmitry Vyukov <dvyukov@google.com>
      Reported-by: NKirill A. Shutemov <kirill@shutemov.name>
      Suggested-by: NJan Kara <jack@suse.cz>
      Reviewed-by: NJan Kara <jack@suse.cz>
      Suggested-by: NMatthew Wilcox <willy@linux.intel.com>
      Tested-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      65f87ee7
  8. 29 1月, 2016 3 次提交
  9. 27 1月, 2016 3 次提交
  10. 26 1月, 2016 1 次提交
    • M
      irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token · 530cbe10
      Marc Zyngier 提交于
      Let's take the (outlandish) example of an interrupt controller
      capable of handling both wired interrupts and PCI MSIs.
      
      With the current code, the PCI MSI domain is going to be tagged
      with DOMAIN_BUS_PCI_MSI, and the wired domain with DOMAIN_BUS_ANY.
      
      Things get hairy when we start looking up the domain for a wired
      interrupt (typically when creating it based on some firmware
      information - DT or ACPI).
      
      In irq_create_fwspec_mapping(), we perform the lookup using
      DOMAIN_BUS_ANY, which is actually used as a wildcard. This gives
      us one chance out of two to end up with the wrong domain, and
      we try to configure a wired interrupt with the MSI domain.
      Everything grinds to a halt pretty quickly.
      
      What we really need to do is to start looking for a domain that
      would uniquely identify a wired interrupt domain, and only use
      DOMAIN_BUS_ANY as a fallback.
      
      In order to solve this, let's introduce a new DOMAIN_BUS_WIRED
      token, which is going to be used exactly as described above.
      Of course, this depends on the irqchip to setup the domain
      bus_token, and nobody had to implement this so far.
      
      Only so far.
      Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Rob Herring <robh+dt@kernel.org>
      Cc: Frank Rowand <frowand.list@gmail.com>
      Cc: Grant Likely <grant.likely@linaro.org>
      Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Jiang Liu <jiang.liu@linux.intel.com>
      Link: http://lkml.kernel.org/r/1453816347-32720-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      530cbe10
  11. 25 1月, 2016 1 次提交
    • A
      net: simplify napi_synchronize() to avoid warnings · facc432f
      Arnd Bergmann 提交于
      The napi_synchronize() function is defined twice: The definition
      for SMP builds waits for other CPUs to be done, while the uniprocessor
      variant just contains a barrier and ignores its argument.
      
      In the mvneta driver, this leads to a warning about an unused variable
      when we lookup the NAPI struct of another CPU and then don't use it:
      
      ethernet/marvell/mvneta.c: In function 'mvneta_percpu_notifier':
      ethernet/marvell/mvneta.c:2910:30: error: unused variable 'other_port' [-Werror=unused-variable]
      
      There are no other CPUs on a UP build, so that code never runs, but
      gcc does not know this.
      
      The nicest solution seems to be to turn the napi_synchronize() helper
      into an inline function for the UP case as well, as that leads gcc to
      not complain about the argument being unused. Once we do that, we can
      also combine the two cases into a single function definition and use
      if(IS_ENABLED()) rather than #ifdef to make it look a bit nicer.
      
      The warning first came up in linux-4.4, but I failed to catch it
      earlier.
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Fixes: f8642885 ("net: mvneta: Statically assign queues to CPUs")
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      facc432f
  12. 24 1月, 2016 5 次提交
  13. 23 1月, 2016 3 次提交
    • R
      dax: add support for fsync/sync · 9973c98e
      Ross Zwisler 提交于
      To properly handle fsync/msync in an efficient way DAX needs to track
      dirty pages so it is able to flush them durably to media on demand.
      
      The tracking of dirty pages is done via the radix tree in struct
      address_space.  This radix tree is already used by the page writeback
      infrastructure for tracking dirty pages associated with an open file,
      and it already has support for exceptional (non struct page*) entries.
      We build upon these features to add exceptional entries to the radix
      tree for DAX dirty PMD or PTE pages at fault time.
      
      [dan.j.williams@intel.com: fix dax_pmd_dbg build warning]
      Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Andreas Dilger <adilger.kernel@dilger.ca>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jan Kara <jack@suse.com>
      Cc: Jeff Layton <jlayton@poochiereds.net>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9973c98e
    • R
      mm: add find_get_entries_tag() · 7e7f7749
      Ross Zwisler 提交于
      Add find_get_entries_tag() to the family of functions that include
      find_get_entries(), find_get_pages() and find_get_pages_tag().  This is
      needed for DAX dirty page handling because we need a list of both page
      offsets and radix tree entries ('indices' and 'entries' in this
      function) that are marked with the PAGECACHE_TAG_TOWRITE tag.
      Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Reviewed-by: NJan Kara <jack@suse.cz>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Andreas Dilger <adilger.kernel@dilger.ca>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeff Layton <jlayton@poochiereds.net>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7e7f7749
    • R
      dax: support dirty DAX entries in radix tree · f9fe48be
      Ross Zwisler 提交于
      Add support for tracking dirty DAX entries in the struct address_space
      radix tree.  This tree is already used for dirty page writeback, and it
      already supports the use of exceptional (non struct page*) entries.
      
      In order to properly track dirty DAX pages we will insert new
      exceptional entries into the radix tree that represent dirty DAX PTE or
      PMD pages.  These exceptional entries will also contain the writeback
      addresses for the PTE or PMD faults that we can use at fsync/msync time.
      
      There are currently two types of exceptional entries (shmem and shadow)
      that can be placed into the radix tree, and this adds a third.  We rely
      on the fact that only one type of exceptional entry can be found in a
      given radix tree based on its usage.  This happens for free with DAX vs
      shmem but we explicitly prevent shadow entries from being added to radix
      trees for DAX mappings.
      
      The only shadow entries that would be generated for DAX radix trees
      would be to track zero page mappings that were created for holes.  These
      pages would receive minimal benefit from having shadow entries, and the
      choice to have only one type of exceptional entry in a given radix tree
      makes the logic simpler both in clear_exceptional_entry() and in the
      rest of DAX.
      Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Andreas Dilger <adilger.kernel@dilger.ca>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jan Kara <jack@suse.com>
      Cc: Jeff Layton <jlayton@poochiereds.net>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f9fe48be