On Wed, Jun 23, 2010 at 7:39 AM, Johannes Stezenbach <js@xxxxxxxxx> wrote: > On Tue, Jun 22, 2010 at 12:38:03PM -0700, Luis R. Rodriguez wrote: >> On Tue, Jun 22, 2010 at 12:37 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxx> wrote: >> > On Tue, Jun 22, 2010 at 12:31 PM, Johannes Stezenbach <js@xxxxxxxxx> wrote: >> >> >> >> Does CONFIG_PCIEASPM provide a way for the user to modifiy >> >> the settings at runtime? >> > >> > You can tune ASPM settings at runtime, regardless of CONFIG_PCIEASPM. See: >> > >> > http://kernel.org/pub/linux/kernel/people/mcgrof/aspm/enable-aspm >> > http://wireless.kernel.org/en/users/Documentation/ASPM >> > >> >> I have a Samsung N130 netbook which has a BIOS setting >> >> called "CPU Power Saving Mode". When enabled it activates >> >> ASPM L1 and L0s for the ethernet chip (Realtek RTL8102e, 100Mbit) >> >> and the PCIE bridge (with the BIOS setting off it's just L1). >> >> The result is that the ethernet througput is reduced to 25Mbit/s. >> > >> > L0s is not going to buy you much gains, getting at least L1 will >> > however. L0s is just a further enhancement. I recommend you test by >> > enabling L1 and L0s, check how longer your battery lasts and then test >> > again with just L1. Then test without both L1 and L0s. >> >> So defaults should always be sane and you should not have to play with >> this stuff, unless you're a hacker, or are testing something for >> development purposes. Tweaking ASPM settings is not something a user >> should have to worry about. Period. > > OK, let me put the question another way: > > If enabling ASPM comes with a performance penalty (which is not unexpected, > there is usually a tradeoff between performance and power consumption), > do you think a boot time option (pcie_aspm=) or compile time option > (CONFIG_PCIEASPM) is the right user interface? > > > But meanwhile I found that CONFIG_PCIEASPM has a runtime > interface, /sys/module/pcie_aspm/parameters/policy. > http://lwn.net/Articles/266585/ > > I have not tested it on my N130 yet. Same thing, its to be used by developers not users, damn it we should just remove this crap. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
