lkml.org 
[lkml]   [2020]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v2 0/2] Replace and improve "mcsafe" with copy_safe()
Date
> When a copy function hits a bad page and the page is not yet known to
> be bad, what does it do? (I.e. the page was believed to be fine but
> the copy function gets #MC.) Does it unmap it right away? What does
> it return?

I suspect that we will only ever find a handful of situations where the
kernel can recover from memory that has gone bad that are worth fixing
(got to be some code path that touches a meaningful fraction of memory,
otherwise we get code complexity without any meaningful payoff).

I don't think we'd want different actions for the cases of "we just found out
now that this page is bad" and "we got a notification an hour ago that this
page had gone bad". Currently we treat those the same for application
errors ... SIGBUS either way[1].

-Tony

[1] well there are options both globally and at the per-process level to have
the "early" notifications delivered right away.
\
 
 \ /
  Last update: 2020-05-04 22:05    [W:0.387 / U:0.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site