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author | Pavel Emelyanov <xemul@openvz.org> | 2008-03-26 23:27:22 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2008-03-26 23:27:22 (GMT) |
commit | 67727184f28c38d06013c6659560bb046c1d9f9c (patch) | |
tree | fce5871c7fe554e05aa61fcc2d2d86afe7befdbc /lib | |
parent | 789e41e6f496022ac1639aaae38ea1943606a9d0 (diff) | |
download | linux-fsl-qoriq-67727184f28c38d06013c6659560bb046c1d9f9c.tar.xz |
[VLAN]: Reduce memory consumed by vlan_groups
Currently each vlan_groupd contains 8 pointers on arrays with 512
pointers on struct net_device each :) Such a construction "in many
cases ... wastes memory".
My proposal is to allow for some of these arrays pointers be NULL,
meaning that there are no devices in it. When a new device is added
to the vlan_group, the appropriate array is allocated.
The check in vlan_group_get_device's is safe, since the pointer
vg->vlan_devices_arrays[x] can only switch from NULL to not-NULL.
The vlan_group_prealloc_vid() is guarded with rtnl lock and is
also safe.
I've checked (I hope that) all the places, that use these arrays
and found, that the register_vlan_dev is the only place, that can
put a vlan device on an empty vlan_group.
Rough calculations shows, that after the patch a setup with a
single vlan dev (or up to 512 vlans with sequential vids) will
occupy approximately 8 times less memory.
The question I have is - does this patch makes sense, or a totally
new structures are required to store the vlan_devs?
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'lib')
0 files changed, 0 insertions, 0 deletions