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Diffstat (limited to 'open_issues/mach_tasks_memory_usage.mdwn')
| -rw-r--r-- | open_issues/mach_tasks_memory_usage.mdwn | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/open_issues/mach_tasks_memory_usage.mdwn b/open_issues/mach_tasks_memory_usage.mdwn index 88e3afb8..9abb7639 100644 --- a/open_issues/mach_tasks_memory_usage.mdwn +++ b/open_issues/mach_tasks_memory_usage.mdwn @@ -10,7 +10,7 @@ License|/fdl]]."]]"""]] [[!tag open_issue_documentation]] -IRC, #hurd, 2011-01-06. +IRC, freenode, #hurd, 2011-01-06 <antrik> hm, odd... vmstat tells me that ~500 MiB of RAM are in use; but the sum of all RSS is <300 MiB... what's the rest? @@ -98,3 +98,50 @@ IRC, #hurd, 2011-01-06. <kilobug> braunr: yeah for bootstrapping issues, makes sense <braunr> it may also depends on the pic/pie options used when building libraries + + +IRC, freenode, #hurd, 2011-07-24 + + < braunr> the panic is probably due to memory shortage + < braunr> so as antrik suggested, use more swap + < antrik> gg0: you could run "vmstat 1" in another terminal to watch memory + usage + < antrik> that way we will know for sure whether it's related + < braunr> antrik: it's trickier than that + < braunr> it depends if the zones used are pageable + < antrik> braunr: well, if it's a zone map exhaustion, then the swap size + won't change anything?... + < braunr> antrik: in this case no, but if the zone is pageable and the + pager (backing anonymous memory) refuses to create memory because it + estimates it's full (all swap space is reserved), it will fail to + < braunr> too + < braunr> but i don't think there are much pageable zones in the kernel + < antrik> yes, but in that case we can see the exhaustion in vmstat :-) + < braunr> many* + < braunr> i'm not sure + < braunr> reserved swap space doesn't mean it's used + < braunr> that's one of the major changes in freebsd 4 or 5 i was + mentioning + < antrik> if it's reserved, it wouldn't show up as "free", would it?... + < braunr> (btw, it's also what makes anonymous memory merging so hard) + < braunr> yes it would + < braunr> well, it could, i'm not sure + < braunr> anonymous memory is considered as a file + < braunr> one big file filled with zeroes, which is the swap partition + < braunr> when you allocate pageable anonymous memory, a part of this + "file" is reserved + < braunr> but i don't know if the reported number if the reserved + (allocated) space, or used (actually containing data) + < braunr> is* + < braunr> i also suspect wired allocations can fail because of a full swap + (because the kernel is unable to make free pages) + < braunr> in this case vmstat will show it + < antrik> what does it matter whether there is data there or not? if it's + reserved, it's not free. if it behaves differently, I'd consider that a + serious bug + < braunr> maybe the original developers intended to monitor its actual + usage + < braunr> antrik: i've just checked how the free count gets updated, and it + looks like it is on both seqnos_memory_object_data_initialize and + seqnos_memory_object_data_write + < braunr> antrik: so i guess reserved memory is accounted for |