W dniu wto, 12.05.2020 o godzinie 10∶05 -0700, użytkownik Zac Medico
> On 5/12/20 3:39 AM, Michał Górny wrote:
> > I'm sorry but I was asking of a more high-level implications.
> > 
> > I presume that this means that more than files of more than one
> > package
> > can be merged simultaneously.  However:
> No, an exclusive lock must be held on vardbapi._fs_lock for this.
> This
> is currently required at least to guarantee that access to the config
> memory file is serialized (config memory is the thing that emerge
> --noconfmem disables, but --noconfmem does not disable this lock).
> We assume that it's probably not worthwhile to try to merge files for
> more than one package at a time, since that would cause them to
> compete
> for IO bandwidth.
> > 1. Are collisions handled correctly then?  i.e. if you start
> > installing
> > A, and then B, and the two packages collide will portage fail
> > before
> > starting to install any file from B?
> There are no guarantees here. However, the risk is minimal, since
> it's
> unlikely that a file collision of this sort would occur. file
> collisions
> are a QA problem that is generally detected and corrected log before
> we
> would encounter a collision of this sort.
> > 2. Are preinst/postinst phases called simultaneously or serialized?
> They're serialized.

Now I'm lost here.  Could you try to explain to me, without getting
into the deep technicalities, how parallel-install achieves better
speed or at doing what is non-parallel-install so slow?

Best regards,
Michał Górny

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