Messages in this thread | | | From | Nikanth Karthikesan <> | Subject | Re: add devname module aliases to allow module on-demand auto-loading | Date | Fri, 21 May 2010 19:09:28 +0530 |
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On Friday 21 May 2010 18:41:38 Kay Sievers wrote: > On Fri, May 21, 2010 at 13:51, Kay Sievers <kay.sievers@vrfy.org> wrote: > > On Fri, May 21, 2010 at 13:34, Alasdair G Kergon <agk@redhat.com> wrote: > > > > There is no harm to make a well-know device node static, it just > > solves a lot of problems, and also makes it possible to work off of a > > static /dev. > > To illustrate: > > On my box without this patch: > dmsetup version > Library version: 1.02.42 (2010-01-14) > /proc/misc: No entry for device-mapper found > Is device-mapper driver missing from kernel? > Failure to communicate with kernel device-mapper driver. > > And the same box just with this patch, nothing else changed: > dmsetup version > Library version: 1.02.42 (2010-01-14) > Driver version: 4.17.0 > > But its up to you to care if device-mapper just works, or if there is > stuff like an init script with modprobe needed to load stuff that > might never be needed. :) >
If this is needed, the dmsetup itself can do a `modprobe dm` instead of printing the message, "Is device-mapper driver missing from kernel?"?
> This is surely not about dynamic vs. static, it is about race-free > on-demand activation of services and subsystems. >
Loading dm-mod alone is enough for `dmsetup version`. But for other operations dm-mod may not be enough, as various other modules like dm-crypt, dm- mirror,... would also be required, depending on the dm table, which may or may not be installed.
Thanks Nikanth
> Thanks, > Kay > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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