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authorThomas Schwinge <thomas@schwinge.name>2011-02-14 17:08:47 +0100
committerThomas Schwinge <thomas@schwinge.name>2011-02-14 17:08:47 +0100
commit4d93ba7548629fff82aa03351132c85d478a8734 (patch)
tree0728298f96c2d90aef5da59cef7bb451704457cc /open_issues/performance/io_system
parent5b1145432bd23441a6ec28cc66410d679b1ebcef (diff)
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+[[!meta copyright="Copyright © 2011 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 open_issue_hurd]]
+
+IRC, #hurd, freenode, 2011-02-13:
+
+ <etenil> youpi: Would libdiskfs/diskfs.h be in the right place to make
+ readahead functions?
+ <youpi> etenil: no, it'd rather be at the memory management layer,
+ i.e. mach, unfortunately
+ <youpi> because that's where you see the page faults
+ <etenil> youpi: Linux also provides a readahead() function for higher level
+ applications. I'll probably have to add the same thing in a place that's
+ higher level than mach
+ <youpi> well, that should just be hooked to the same common implementation
+ <etenil> the man page for readahead() also states that portable
+ applications should avoid it, but it could be benefic to have it for
+ portability
+ <youpi> it's not in posix indeed
+
+IRC, #hurd, freenode, 2011-02-14:
+
+ <etenil> youpi: I've investigated prefetching (readahead) techniques. One
+ called DiskSeen seems really efficient. I can't tell yet if it's patented
+ etc. but I'll keep you informed
+ <youpi> don't bother with complicated techniques, even the most simple ones
+ will be plenty :)
+ <etenil> it's not complicated really
+ <youpi> the matter is more about how to plug it into mach
+ <etenil> ok
+ <youpi> then don't bother with potential pattents
+ <antrik> etenil: please take a look at the work KAM did for last year's
+ GSoC
+ <youpi> just use a trivial technique :)
+ <etenil> ok, i'll just go the easy way then
+
+ <braunr> antrik: what was etenil referring to when talking about
+ prefetching ?
+ <braunr> oh, madvise() stuff
+ <braunr> i could help him with that