1. 14 2月, 2012 1 次提交
  2. 27 8月, 2011 1 次提交
    • J
      ppp: Move the PPP drivers · 224cf5ad
      Jeff Kirsher 提交于
      Move the PPP drivers into drivers/net/ppp/ and make the
      necessary Kconfig and Makefile changes.
      
      CC: Paul Mackerras <paulus@samba.org>
      CC: Frank Cusack <fcusack@fcusack.com>
      CC: Michal Ostrowski <mostrows@speakeasy.net>
      CC: Michal Ostrowski <mostrows@earthlink.net>
      CC: Dmitry Kozlov <xeb@mail.ru>
      Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      224cf5ad
  3. 27 7月, 2011 1 次提交
  4. 31 3月, 2011 1 次提交
  5. 21 1月, 2011 3 次提交
  6. 11 1月, 2011 1 次提交
  7. 29 12月, 2010 1 次提交
    • S
      ppp: allow disabling multilink protocol ID compression · d39cd5e9
      stephen hemminger 提交于
      Linux would not connect to other router running old version Cisco IOS (12.0).
      This is most likely a bug in that version of IOS, since it is fixed
      in later versions. As a workaround this patch allows a module parameter
      to be set to disable compressing the protocol ID.
      
      See: https://bugzilla.vyatta.com/show_bug.cgi?id=3979
      
      RFC 1990 allows an implementation to formulate MP fragments as if protocol
      compression had been negotiated.  This allows us to always send compressed
      protocol IDs.  But some implementations don't accept MP fragments with
      compressed protocol IDs.  This parameter allows us to interoperate with
      them.  The default value of the configurable parameter is the same as the
      current behavior:  protocol compression is enabled.  If protocol compression
      is disabled we will not send compressed protocol IDs.
      
      This is based on an earlier patch by Bob Gilligan (using a sysctl).
      Module parameter is writable to allow for enabling even if ppp
      is already loaded for other uses.
      Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
      Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d39cd5e9
  8. 29 11月, 2010 1 次提交
  9. 20 11月, 2010 1 次提交
    • E
      filter: optimize sk_run_filter · 93aaae2e
      Eric Dumazet 提交于
      Remove pc variable to avoid arithmetic to compute fentry at each filter
      instruction. Jumps directly manipulate fentry pointer.
      
      As the last instruction of filter[] is guaranteed to be a RETURN, and
      all jumps are before the last instruction, we dont need to check filter
      bounds (number of instructions in filter array) at each iteration, so we
      remove it from sk_run_filter() params.
      
      On x86_32 remove f_k var introduced in commit 57fe93b3
      (filter: make sure filters dont read uninitialized memory)
      
      Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to
      avoid too many ifdefs in this code.
      
      This helps compiler to use cpu registers to hold fentry and A
      accumulator.
      
      On x86_32, this saves 401 bytes, and more important, sk_run_filter()
      runs much faster because less register pressure (One less conditional
      branch per BPF instruction)
      
      # size net/core/filter.o net/core/filter_pre.o
         text    data     bss     dec     hex filename
         2948       0       0    2948     b84 net/core/filter.o
         3349       0       0    3349     d15 net/core/filter_pre.o
      
      on x86_64 :
      # size net/core/filter.o net/core/filter_pre.o
         text    data     bss     dec     hex filename
         5173       0       0    5173    1435 net/core/filter.o
         5224       0       0    5224    1468 net/core/filter_pre.o
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: NChangli Gao <xiaosuo@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93aaae2e
  10. 15 10月, 2010 1 次提交
    • A
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann 提交于
      All file_operations should get a .llseek operation so we can make
      nonseekable_open the default for future file operations without a
      .llseek pointer.
      
      The three cases that we can automatically detect are no_llseek, seq_lseek
      and default_llseek. For cases where we can we can automatically prove that
      the file offset is always ignored, we use noop_llseek, which maintains
      the current behavior of not returning an error from a seek.
      
      New drivers should normally not use noop_llseek but instead use no_llseek
      and call nonseekable_open at open time.  Existing drivers can be converted
      to do the same when the maintainer knows for certain that no user code
      relies on calling seek on the device file.
      
      The generated code is often incorrectly indented and right now contains
      comments that clarify for each added line why a specific variant was
      chosen. In the version that gets submitted upstream, the comments will
      be gone and I will manually fix the indentation, because there does not
      seem to be a way to do that using coccinelle.
      
      Some amount of new code is currently sitting in linux-next that should get
      the same modifications, which I will do at the end of the merge window.
      
      Many thanks to Julia Lawall for helping me learn to write a semantic
      patch that does all this.
      
      ===== begin semantic patch =====
      // This adds an llseek= method to all file operations,
      // as a preparation for making no_llseek the default.
      //
      // The rules are
      // - use no_llseek explicitly if we do nonseekable_open
      // - use seq_lseek for sequential files
      // - use default_llseek if we know we access f_pos
      // - use noop_llseek if we know we don't access f_pos,
      //   but we still want to allow users to call lseek
      //
      @ open1 exists @
      identifier nested_open;
      @@
      nested_open(...)
      {
      <+...
      nonseekable_open(...)
      ...+>
      }
      
      @ open exists@
      identifier open_f;
      identifier i, f;
      identifier open1.nested_open;
      @@
      int open_f(struct inode *i, struct file *f)
      {
      <+...
      (
      nonseekable_open(...)
      |
      nested_open(...)
      )
      ...+>
      }
      
      @ read disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      <+...
      (
         *off = E
      |
         *off += E
      |
         func(..., off, ...)
      |
         E = *off
      )
      ...+>
      }
      
      @ read_no_fpos disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ write @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      <+...
      (
        *off = E
      |
        *off += E
      |
        func(..., off, ...)
      |
        E = *off
      )
      ...+>
      }
      
      @ write_no_fpos @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ fops0 @
      identifier fops;
      @@
      struct file_operations fops = {
       ...
      };
      
      @ has_llseek depends on fops0 @
      identifier fops0.fops;
      identifier llseek_f;
      @@
      struct file_operations fops = {
      ...
       .llseek = llseek_f,
      ...
      };
      
      @ has_read depends on fops0 @
      identifier fops0.fops;
      identifier read_f;
      @@
      struct file_operations fops = {
      ...
       .read = read_f,
      ...
      };
      
      @ has_write depends on fops0 @
      identifier fops0.fops;
      identifier write_f;
      @@
      struct file_operations fops = {
      ...
       .write = write_f,
      ...
      };
      
      @ has_open depends on fops0 @
      identifier fops0.fops;
      identifier open_f;
      @@
      struct file_operations fops = {
      ...
       .open = open_f,
      ...
      };
      
      // use no_llseek if we call nonseekable_open
      ////////////////////////////////////////////
      @ nonseekable1 depends on !has_llseek && has_open @
      identifier fops0.fops;
      identifier nso ~= "nonseekable_open";
      @@
      struct file_operations fops = {
      ...  .open = nso, ...
      +.llseek = no_llseek, /* nonseekable */
      };
      
      @ nonseekable2 depends on !has_llseek @
      identifier fops0.fops;
      identifier open.open_f;
      @@
      struct file_operations fops = {
      ...  .open = open_f, ...
      +.llseek = no_llseek, /* open uses nonseekable */
      };
      
      // use seq_lseek for sequential files
      /////////////////////////////////////
      @ seq depends on !has_llseek @
      identifier fops0.fops;
      identifier sr ~= "seq_read";
      @@
      struct file_operations fops = {
      ...  .read = sr, ...
      +.llseek = seq_lseek, /* we have seq_read */
      };
      
      // use default_llseek if there is a readdir
      ///////////////////////////////////////////
      @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier readdir_e;
      @@
      // any other fop is used that changes pos
      struct file_operations fops = {
      ... .readdir = readdir_e, ...
      +.llseek = default_llseek, /* readdir is present */
      };
      
      // use default_llseek if at least one of read/write touches f_pos
      /////////////////////////////////////////////////////////////////
      @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read.read_f;
      @@
      // read fops use offset
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = default_llseek, /* read accesses f_pos */
      };
      
      @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ... .write = write_f, ...
      +	.llseek = default_llseek, /* write accesses f_pos */
      };
      
      // Use noop_llseek if neither read nor write accesses f_pos
      ///////////////////////////////////////////////////////////
      
      @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      identifier write_no_fpos.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ...
       .write = write_f,
       .read = read_f,
      ...
      +.llseek = noop_llseek, /* read and write both use no f_pos */
      };
      
      @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write_no_fpos.write_f;
      @@
      struct file_operations fops = {
      ... .write = write_f, ...
      +.llseek = noop_llseek, /* write uses no f_pos */
      };
      
      @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      @@
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = noop_llseek, /* read uses no f_pos */
      };
      
      @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      @@
      struct file_operations fops = {
      ...
      +.llseek = noop_llseek, /* no read or write fn */
      };
      ===== End semantic patch =====
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  11. 05 10月, 2010 1 次提交
  12. 14 9月, 2010 1 次提交
  13. 13 7月, 2010 1 次提交
    • A
      net: autoconvert trivial BKL users to private mutex · 15fd0cd9
      Arnd Bergmann 提交于
      All these files use the big kernel lock in a trivial
      way to serialize their private file operations,
      typically resulting from an earlier semi-automatic
      pushdown from VFS.
      
      None of these drivers appears to want to lock against
      other code, and they all use the BKL as the top-level
      lock in their file operations, meaning that there
      is no lock-order inversion problem.
      
      Consequently, we can remove the BKL completely,
      replacing it with a per-file mutex in every case.
      Using a scripted approach means we can avoid
      typos.
      
      file=$1
      name=$2
      if grep -q lock_kernel ${file} ; then
          if grep -q 'include.*linux.mutex.h' ${file} ; then
                  sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
          else
                  sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
          fi
          sed -i ${file} \
              -e "/^#include.*linux.mutex.h/,$ {
                      1,/^\(static\|int\|long\)/ {
                           /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);
      
      } }"  \
          -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
          -e '/[      ]*cycle_kernel_lock();/d'
      else
          sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                      -e '/cycle_kernel_lock()/d'
      fi
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: netdev@vger.kernel.org
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      15fd0cd9
  14. 05 6月, 2010 1 次提交
  15. 02 6月, 2010 1 次提交
  16. 31 5月, 2010 2 次提交
  17. 26 5月, 2010 1 次提交
    • K
      driver core: add devname module aliases to allow module on-demand auto-loading · 578454ff
      Kay Sievers 提交于
      This adds:
        alias: devname:<name>
      to some common kernel modules, which will allow the on-demand loading
      of the kernel module when the device node is accessed.
      
      Ideally all these modules would be compiled-in, but distros seems too
      much in love with their modularization that we need to cover the common
      cases with this new facility. It will allow us to remove a bunch of pretty
      useless init scripts and modprobes from init scripts.
      
      The static device node aliases will be carried in the module itself. The
      program depmod will extract this information to a file in the module directory:
        $ cat /lib/modules/2.6.34-00650-g537b60d1-dirty/modules.devname
        # Device nodes to trigger on-demand module loading.
        microcode cpu/microcode c10:184
        fuse fuse c10:229
        ppp_generic ppp c108:0
        tun net/tun c10:200
        dm_mod mapper/control c10:235
      
      Udev will pick up the depmod created file on startup and create all the
      static device nodes which the kernel modules specify, so that these modules
      get automatically loaded when the device node is accessed:
        $ /sbin/udevd --debug
        ...
        static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184
        static_dev_create_from_modules: mknod '/dev/fuse' c10:229
        static_dev_create_from_modules: mknod '/dev/ppp' c108:0
        static_dev_create_from_modules: mknod '/dev/net/tun' c10:200
        static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235
        udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666
        udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666
      
      A few device nodes are switched to statically allocated numbers, to allow
      the static nodes to work. This might also useful for systems which still run
      a plain static /dev, which is completely unsafe to use with any dynamic minor
      numbers.
      
      Note:
      The devname aliases must be limited to the *common* and *single*instance*
      device nodes, like the misc devices, and never be used for conceptually limited
      systems like the loop devices, which should rather get fixed properly and get a
      control node for losetup to talk to, instead of creating a random number of
      device nodes in advance, regardless if they are ever used.
      
      This facility is to hide the mess distros are creating with too modualized
      kernels, and just to hide that these modules are not compiled-in, and not to
      paper-over broken concepts. Thanks! :)
      
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Cc: Chris Mason <chris.mason@oracle.com>
      Cc: Alasdair G Kergon <agk@redhat.com>
      Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
      Cc: Ian Kent <raven@themaw.net>
      Signed-Off-By: NKay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      578454ff
  18. 04 5月, 2010 2 次提交
  19. 04 4月, 2010 1 次提交
  20. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  21. 19 1月, 2010 1 次提交
    • L
      ppp_generic.c severly whitespace damanged by 9c705260 · fa44a73c
      Lennart Sorensen 提交于
      I was just looking at ppp_generic, and noticed that it fairly recently
      (as in the last year) got rather mangled with many spaces turned into tabs
      in places they very much shouldn't have been.  I tracked it down to commit
      9c705260 (ppp: ppp_mp_explode() redesign).
      
      I am amazed if that patch passed the patch checking script.  I have no
      idea what kind of weird editor setting did this, but it has to have been a
      weird editor setting or a very unfortunate search and replace gone wrong.
      I only found it trying to apply a patch I was playing with and wondering
      why it wouldn't apply.  Then I found there were tabs in the middle of
      comments that used to be spaces.
      
      Well here is a patch that should fix it up as far as I can tell.
      
      Purely whitespace repair.  No actual code changes.
      Signed-off-by: NLen Sorensen <lsorense@csclub.uwaterloo.ca>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fa44a73c
  22. 04 12月, 2009 1 次提交
  23. 02 12月, 2009 1 次提交
  24. 18 11月, 2009 1 次提交
  25. 17 11月, 2009 1 次提交
    • B
      ppp: fix BUG on non-linear SKB (multilink receive) · 82b3cc1a
      Ben McKeegan 提交于
      PPP does not correctly call pskb_may_pull() on all necessary receive paths
      before reading the PPP protocol, thus causing PPP to report seemingly
      random 'unsupported protocols' and eventually trigger BUG_ON(skb->len <
      skb->data_len) in skb_pull_rcsum() when receiving multilink protocol in
      non-linear skbs.
      
      ppp_receive_nonmp_frame() does not call pskb_may_pull() before reading the
      protocol number.  For the non-mp receive path this is not a problem, as
      this check is done in ppp_receive_frame().  For the mp receive path,
      ppp_mp_reconstruct() usually copies the data into a new linear skb.
      However, in the case where the frame is made up of a single mp fragment,
      the mp header is pulled and the existing skb used.  This skb was then
      passed to ppp_receive_nonmp_frame() without checking if the encapsulated
      protocol header could safely be read.
      Signed-off-by: NBen McKeegan <ben@netservers.co.uk>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      82b3cc1a
  26. 01 9月, 2009 1 次提交
  27. 20 8月, 2009 1 次提交
    • D
      ppp_generic: Help GCC see that 'flen' is always initialized. · 886f9fe6
      David S. Miller 提交于
      It's too stupid to see that we always set flen to something
      before we use it in ppp_mp_explode():
      
      drivers/net/ppp_generic.c: In function 'ppp_push':
      drivers/net/ppp_generic.c:1314: warning: 'flen' may be used uninitialized in this function
      drivers/net/ppp_generic.c:1314: note: 'flen' was declared here
      
      This started warning after commit a53a8b56
      ("ppp: fix lost fragments in ppp_mp_explode() (resubmit)")
      
      So just put an explicit unconditional initialization there to
      hush it up.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      886f9fe6
  28. 03 8月, 2009 1 次提交
    • B
      ppp: fix lost fragments in ppp_mp_explode() (resubmit) · a53a8b56
      Ben McKeegan 提交于
      This patch fixes the corner cases where the sum of MTU of the free
      channels (adjusted for fragmentation overheads) is less than the MTU
      of PPP link.  There are at least 3 situations where this case might
      arise:
      
      - some of the channels are busy
      
      - the multilink session is running in a degraded state (i.e. with less
      than its full complement of active channels)
      
      - by design, where multilink protocol is being used to artificially
      increase the effective link MTU of a single link.
      
      Without this patch, at most 1 fragment is ever sent per free channel
      for a given PPP frame and any remaining part of the PPP frame that
      does not fit into those fragments is silently discarded.
      
      This patch restores the original behaviour which was broken by commit
      9c705260 'ppp:ppp_mp_explode()
      redesign'.  Once all 'free' channels have been given a fragment, an
      additional fragment is queued to each available channel in turn, as many
      times as necessary, until the entire PPP frame has been consumed.
      Signed-off-by: NBen McKeegan <ben@netservers.co.uk>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a53a8b56
  29. 06 7月, 2009 1 次提交
  30. 20 5月, 2009 1 次提交
  31. 14 3月, 2009 1 次提交
    • G
      ppp: ppp_mp_explode() redesign · 9c705260
      Gabriele Paoloni 提交于
      I found the PPP subsystem to not work properly when connecting channels
      with different speeds to the same bundle.
      
      Problem Description:
      
      As the "ppp_mp_explode" function fragments the sk_buff buffer evenly
      among the PPP channels that are connected to a certain PPP unit to
      make up a bundle, if we are transmitting using an upper layer protocol
      that requires an Ack before sending the next packet (like TCP/IP for
      example), we will have a bandwidth bottleneck on the slowest channel
      of the bundle.
      
      Let's clarify by an example. Let's consider a scenario where we have
      two PPP links making up a bundle: a slow link (10KB/sec) and a fast
      link (1000KB/sec) working at the best (full bandwidth). On the top we
      have a TCP/IP stack sending a 1000 Bytes sk_buff buffer down to the
      PPP subsystem. The "ppp_mp_explode" function will divide the buffer in
      two fragments of 500B each (we are neglecting all the headers, crc,
      flags etc?.). Before the TCP/IP stack sends out the next buffer, it
      will have to wait for the ACK response from the remote peer, so it
      will have to wait for both fragments to have been sent over the two
      PPP links, received by the remote peer and reconstructed. The
      resulting behaviour is that, rather than having a bundle working
      @1010KB/sec (the sum of the channels bandwidths), we'll have a bundle
      working @20KB/sec (the double of the slowest channels bandwidth).
      
      
      Problem Solution:
      
      The problem has been solved by redesigning the "ppp_mp_explode"
      function in such a way to make it split the sk_buff buffer according
      to the speeds of the underlying PPP channels (the speeds of the serial
      interfaces respectively attached to the PPP channels). Referring to
      the above example, the redesigned "ppp_mp_explode" function will now
      divide the 1000 Bytes buffer into two fragments whose sizes are set
      according to the speeds of the channels where they are going to be
      sent on (e.g .  10 Byets on 10KB/sec channel and 990 Bytes on
      1000KB/sec channel).  The reworked function grants the same
      performances of the original one in optimal working conditions (i.e. a
      bundle made up of PPP links all working at the same speed), while
      greatly improving performances on the bundles made up of channels
      working at different speeds.
      Signed-off-by: NGabriele Paoloni <gabriele.paoloni@intel.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9c705260
  32. 27 2月, 2009 2 次提交
  33. 18 2月, 2009 1 次提交
  34. 10 2月, 2009 1 次提交
  35. 22 1月, 2009 1 次提交