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  1. 23 3月, 2017 4 次提交
    • D
      Merge branch 'r8152-rx-settings' · 8fb106b2
      由 David S. Miller 提交于 
      Hayes Wang says:

====================
r8152: fix the rx settings of RTL8153

The RMS and the rx early size should base on the same rx size. However,
the RMS is set to 9K bytes now and the rx early depends on mtu. For using
the rx buffer effectively, sync the two settings according to the mtu.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8fb106b2
    • H
      r8152: fix the rx early size of RTL8153 · b20cb60e
      由 hayeswang 提交于 
      revert commit a59e6d81 ("r8152: correct the rx early size") and
fix the rx early size as

	(rx buffer size - rx packet size - rx desc size - alignment) / 4
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b20cb60e
    • H
      r8152: set the RMS of RTL8153 according to the mtu · 210c4f70
      由 hayeswang 提交于 
      Set the received maximum size (RMS) according to the mtu size. It is
unnecessary to receive a packet which is more than the size we could
transmit. Besides, this could let the rx buffer be used effectively.
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      210c4f70
    • T
      cgroup, net_cls: iterate the fds of only the tasks which are being migrated · a05d4fd9
      由 Tejun Heo 提交于 
      The net_cls controller controls the classid field of each socket which
is associated with the cgroup.  Because the classid is per-socket
attribute, when a task migrates to another cgroup or the configured
classid of the cgroup changes, the controller needs to walk all
sockets and update the classid value, which was implemented by
3b13758f ("cgroups: Allow dynamically changing net_classid").

While the approach is not scalable, migrating tasks which have a lot
of fds attached to them is rare and the cost is born by the ones
initiating the operations.  However, for simplicity, both the
migration and classid config change paths call update_classid() which
scans all fds of all tasks in the target css.  This is an overkill for
the migration path which only needs to cover a much smaller subset of
tasks which are actually getting migrated in.

On cgroup v1, this can lead to unexpected scalability issues when one
tries to migrate a task or process into a net_cls cgroup which already
contains a lot of fds.  Even if the migration traget doesn't have many
to get scanned, update_classid() ends up scanning all fds in the
target cgroup which can be extremely numerous.

Unfortunately, on cgroup v2 which doesn't use net_cls, the problem is
even worse.  Before bfc2cf6f ("cgroup: call subsys->*attach() only
for subsystems which are actually affected by migration"), cgroup core
would call the ->css_attach callback even for controllers which don't
see actual migration to a different css.

As net_cls is always disabled but still mounted on cgroup v2, whenever
a process is migrated on the cgroup v2 hierarchy, net_cls sees
identity migration from root to root and cgroup core used to call
->css_attach callback for those.  The net_cls ->css_attach ends up
calling update_classid() on the root net_cls css to which all
processes on the system belong to as the controller isn't used.  This
makes any cgroup v2 migration O(total_number_of_fds_on_the_system)
which is horrible and easily leads to noticeable stalls triggering RCU
stall warnings and so on.

The worst symptom is already fixed in upstream by bfc2cf6f
("cgroup: call subsys->*attach() only for subsystems which are
actually affected by migration"); however, backporting that commit is
too invasive and we want to avoid other cases too.

This patch updates net_cls's cgrp_attach() to iterate fds of only the
processes which are actually getting migrated.  This removes the
surprising migration cost which is dependent on the total number of
fds in the target cgroup.  As this leaves write_classid() the only
user of update_classid(), open-code the helper into write_classid().
Reported-by: NDavid Goode <dgoode@fb.com>
Fixes: 3b13758f ("cgroups: Allow dynamically changing net_classid")
Cc: stable@vger.kernel.org # v4.4+
Cc: Nina Schiff <ninasc@fb.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a05d4fd9
  3. 22 3月, 2017 20 次提交
  5. 17 3月, 2017 11 次提交
  7. 16 3月, 2017 5 次提交