On Thu, May 25, 2017 at 12:01 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote: > On Thu, May 25, 2017 at 11:26 AM, Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: >> On Thu, May 25, 2017 at 08:06:03PM +0200, Luis R. Rodriguez wrote: >>> On Thu, May 25, 2017 at 10:38:40AM -0700, Luis R. Rodriguez wrote: >>> > On Thu, May 25, 2017 at 10:30 AM, Dmitry Torokhov >>> > > There is >>> > > no slippery slope for systems to move away, no need to backport >>> > > anything. We seem to agree that a better solution is possible (throttle >>> > > number of concurrently running modprobes without killing requesters), >>> > > and with that solution the band-aid will no longer be needed. >>> > > >>> > > So please implement and post the proper fix for the issue. >>> > >>> > Alright, will do away with this patch and just go for the jugular of the issue. >>> >>> I gave this some more thought, even if we go with the throttling right away in >>> practice you'll end up with a dmesg notice of a throttle kicking in once you *do* >> >> So remove it. The warning was meaningful when we rejected requests, now >> it is not. > > Great. > >>> reach this. We are forcing only 50 concurrent threads and making this a static >>> limit with no good reason than 2.3.38 days evaluation from 16 years ago (2000). >>> If we throttle we are going to throttle with a 2.3.38 days limit. And you >>> advocate that ? >> >> Yes. Can you give me reason why slamming the system with more than 50 >> modprobes is a good idea in 4.12 days? Does the increased limit >> decreases boot time? By how much? > > If in practice we are not hitting the limit the point is moot, and > when we do I agree we can re-evaluate. With my stress test driver on a > test case we can push as hard as bringing out the OOM killer even if > we throttle, fun. Alright, I don't see these OOMs anymore *after* I actually nuked that patch which incremented the kmod limit. The reason we can OOM is finit_module() can consume gobs of memory, the current value then seems fair, and work well for my tests provided we do use the proper throttle. Will respin. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
