diff options
author | Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> | 2012-05-30 08:25:19 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-05-31 18:18:16 -0400 |
commit | 25426b794efdc70dde7fd3134dc56fac3e7d562d (patch) | |
tree | 800ef2d96fbf9cc6e8973d517f714edbda6b4fc2 /lib/bug.c | |
parent | 0cfd32b736ae0c36b42697584811042726c07cba (diff) |
bql: Avoid unneeded limit decrement.
When below pattern is observed,
TIME
dql_queued() dql_completed() |
a) initial state |
|
b) X bytes queued V
c) Y bytes queued
d) X bytes completed
e) Z bytes queued
f) Y bytes completed
a) dql->limit has already some value and there is no in-flight packet.
b) X bytes queued.
c) Y bytes queued and excess limit.
d) X bytes completed and dql->prev_ovlimit is set and also
dql->prev_num_queued is set Y.
e) Z bytes queued.
f) Y bytes completed. inprogress and prev_inprogress are true.
At f), according to the comment, all_prev_completed becomes
true and limit should be increased. But POSDIFF() ignores
(completed == dql->prev_num_queued) case, so limit is decreased.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Denys Fedoryshchenko <denys@visp.net.lb>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/bug.c')
0 files changed, 0 insertions, 0 deletions