summaryrefslogtreecommitdiffstats
path: root/usr
diff options
context:
space:
mode:
authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2006-08-04 16:36:18 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2006-08-04 22:59:51 -0700
commitc4c0ce5c57ef0ca47a4428a14de6b5c8cdf8de8a (patch)
tree762530925f75495b9d2b8bb35702060e7e2fa9ae /usr
parent30a584d944fbd599d4a8f470f75bf7af1a15b466 (diff)
downloadlinux-c4c0ce5c57ef0ca47a4428a14de6b5c8cdf8de8a.tar.bz2
[PKT_SCHED] RED: Fix overflow in calculation of queue average
Overflow can occur very easily with 32 bits, e.g., with 1 second us_idle is approx. 2^20, which leaves only 11-Wlog bits for queue length. Since the EWMA exponent is typically around 9, queue lengths larger than 2^2 cause overflow. Whether the affected branch is taken when us_idle is as high as 1 second, depends on Scell_log, but with rather reasonable configuration Scell_log is large enough to cause p->Stab to have zero index, which always results zero shift (typically also few other small indices result in zero shift). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'usr')
0 files changed, 0 insertions, 0 deletions