Panic: vm_fault: fault on nofault entry

[Anton Yuzhaninov]

On 09/30/17 04:18, Konstantin Belousov wrote:
>> I have panics when I try to use nginx on my notebook. When sendfile is
>> enabled it is easy to trigger panic, after disabling sendfile I've got
>> no panics so far and I think that panic is triggered by using sendfile.
>>
>> Root filesystem - UFS on GELI whith 8k sectorsize.
>>
>> GELI with sectorsize large than page size is non-standard configuration,
>> and I've got problem because of this in the past:
>> https://lists.freebsd.org/pipermail/freebsd-fs/2016-October/023957.html
>>
>> but it was fixed in:
>> https://svnweb.freebsd.org/changeset/base/307626
> Well, it was fixed by replacing the code path for normal page in by
> the less buggy pager. The sendfile path was not touched, it still uses
> the generic pager with all its bugs sitting in place.
> 
> There is no way around it, you cannot use block size > page size for
> sendfile, and there are more issues, e.g. with the simultaneous file
> truncation.
> 

Thanks for explaining. On a desktop I can easily avoid using sendfile(2).

Hard part for me was to find out that panic was triggered by sendfile
(and to something else).