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author | https://me.yahoo.com/a/g3Ccalpj0NhN566pHbUl6i9QF0QEkrhlfPM-#b1c14 <diana@web> | 2015-02-16 20:08:03 +0100 |
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committer | GNU Hurd web pages engine <web-hurd@gnu.org> | 2015-02-16 20:08:03 +0100 |
commit | 95878586ec7611791f4001a4ee17abf943fae3c1 (patch) | |
tree | 847cf658ab3c3208a296202194b16a6550b243cf /open_issues/managed_runtime_initiative.mdwn | |
parent | 8063426bf7848411b0ef3626d57be8cb4826715e (diff) | |
download | web-95878586ec7611791f4001a4ee17abf943fae3c1.tar.gz web-95878586ec7611791f4001a4ee17abf943fae3c1.tar.bz2 web-95878586ec7611791f4001a4ee17abf943fae3c1.zip |
rename open_issues.mdwn to service_solahart_jakarta_selatan__082122541663.mdwn
Diffstat (limited to 'open_issues/managed_runtime_initiative.mdwn')
-rw-r--r-- | open_issues/managed_runtime_initiative.mdwn | 72 |
1 files changed, 0 insertions, 72 deletions
diff --git a/open_issues/managed_runtime_initiative.mdwn b/open_issues/managed_runtime_initiative.mdwn deleted file mode 100644 index 7a880beb..00000000 --- a/open_issues/managed_runtime_initiative.mdwn +++ /dev/null @@ -1,72 +0,0 @@ -[[!meta copyright="Copyright © 2013 Free Software Foundation, Inc."]] - -[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable -id="license" text="Permission is granted to copy, distribute and/or modify this -document under the terms of the GNU Free Documentation License, Version 1.2 or -any later version published by the Free Software Foundation; with no Invariant -Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license -is included in the section entitled [[GNU Free Documentation -License|/fdl]]."]]"""]] - -[[!tag open_issue_gnumach]] - - -# IRC, freenode, #hurd, 2013-04-02 - - <psockali> hi again, maybe someone has some metrics - <psockali> is mprotect / munprotect faster in hurd then in linux ? - <pinotree> ? - <psockali> can i protected a memory page against write access in hurd - <psockali> and if so, is it a fast operation ? - <youpi> you can, I never measured, but it's probably the same cost as in - linux - <youpi> I don't see why it would be different, as it boils down to the same - x86 trick - <psockali> but i suppose it is part of the mach kernel doing the protection - and not part of the unix layer ? - <youpi> it is - <youpi> the unix layer doesn't have mm control - <youpi> it has to ask the kernel - <braunr> it's slower on mach, as it's less optimized because of historical - reasons - <braunr> but that's about it - <youpi> less optimized, how so? - <braunr> well, more entry fragmentation - <youpi> in the end you mark the page table and flush the tlb - <braunr> yes - <braunr> the high level virtual memory layer is a bit slower - <youpi> but fragmentation doesn't come into play it you just have one - memory object, does it? - <braunr> it does, as it's about memory areas, not objects - <braunr> the object is merely a backing store - <braunr> protection, inheritance, copy on write are all area (vm_map_entry) - attributes - <braunr> also, some operations affect all the address spaces where a - physical page is mapped - <braunr> although i think linux does the same thing as mach/bsd now - <youpi> but mprotect/munprotect doesn't, does it? - <braunr> no - <braunr> or perhaps by side effect, in some situations, i'm not sure - <braunr> i think it depends if the memory is shared between processes, but - i don't remember the details and can't think of a proper example right - now - <braunr> but anyway, "slower" here is negligible unless address spaces are - really huge and filled with lots of map entries - <braunr> psockali: why do you ask ? - <psockali> can i post a link here ? - <braunr> about what ? - <psockali> it's regarding azul / managed runtime initiative - <psockali> a GC for java - <braunr> why not - <braunr> although i don't see the point for now :) - <psockali> they have a custom MM management module for their GC as linux - kernel modul - <psockali> and i was wondering if mach would be any faster then linux in - that aspect - <psockali> - http://stackoverflow.com/questions/3358545/whats-actually-in-the-managed-runtime-initiatives-kernel-patches-and-jvm - <braunr> psockali: generally speaking, mach is slower than linux because of - its age and the fact it didn't receive as much attention and - microoptimization as linux did - <braunr> psockali: about this article, there is no reason mach would be - faster |