diff options
Diffstat (limited to 'hurd')
| -rw-r--r-- | hurd/debugging/rpctrace.mdwn | 37 | ||||
| -rw-r--r-- | hurd/translator/tmpfs/tmpfs_vs_defpager.mdwn | 37 | ||||
| -rw-r--r-- | hurd/virtual_file_system/discussion.mdwn | 39 |
3 files changed, 113 insertions, 0 deletions
diff --git a/hurd/debugging/rpctrace.mdwn b/hurd/debugging/rpctrace.mdwn index f7136056..fd24f081 100644 --- a/hurd/debugging/rpctrace.mdwn +++ b/hurd/debugging/rpctrace.mdwn @@ -52,6 +52,43 @@ See `rpctrace --help` about how to use it. <antrik> note that there is a number of known bugs in rpctrace, for which zhengda has sent patches... though I haven't reviewed all of them I think <antrik> there are some nasty Mach operations that are really hard to proxy -- but I don't think the auth mechanism needs any of these... +* IRC, freenode, #hurd, 2011-11-04 + + [[!taglink open_issue_documentation]] + + <mcsim> hello. Are there any documentation about understanding output + of rpctrace? + <braunr> no + <braunr> you should read the source code, best doc available + <braunr> if you have too many numbers and almost no symbolc names, + you're lacking rpc definition lists + <braunr> check that the gnumach-common package is installed, as it + provides the gnumach definitions + <braunr> (the glibc ones are almost always available) + <braunr> with those two, you should be fine for the beginning + <mcsim> gnumach-common is installed. And what is the name for glibc + package for gnumach definitions. + <mcsim> Also I'm using libraries specified by LD_LIBRARY_PATH. Does it + make influence on absence of symbolic names? + <braunr> no + <braunr> rpctrace --help + <braunr> see the --rpc-list=FILE option + <braunr> the default lists are in /usr/share/msgids/, with the .msgids + extension + <braunr> $ dpkg -S msgids + <braunr> gnumach-common: /usr/share/msgids/gnumach.msgids + <braunr> hurd: /usr/share/msgids/hurd.msgids + <braunr> ok, glibc has none, it's the hurd + <braunr> for more details about the output, read the source code + <braunr> it shouldn't be that hard to grasp + <mcsim> -I /usr/share/msgids helped + <mcsim> thank you + <braunr> it shouldn't have, it's the default path + <mcsim> but symbolic names appeared + <braunr> well, that's weird :) + <pinotree> braunr: the output of rpctrace --help should tell the + default dir for msgids + # See Also diff --git a/hurd/translator/tmpfs/tmpfs_vs_defpager.mdwn b/hurd/translator/tmpfs/tmpfs_vs_defpager.mdwn index a9317c21..5228515f 100644 --- a/hurd/translator/tmpfs/tmpfs_vs_defpager.mdwn +++ b/hurd/translator/tmpfs/tmpfs_vs_defpager.mdwn @@ -233,3 +233,40 @@ See also: [[open_issues/resource_management_problems/pagers]]. I have never looked at it. [[open_issues/mach-defpager_vs_defpager]]. + + +# IRC, freenode, #hurd, 2011-11-08 + + <mcsim> who else uses defpager besides tmpfs and kernel? + <braunr> normally, nothing directly + <mcsim> than why tmpfs should use defpager? + <braunr> it's its backend + <braunr> backign store rather + <braunr> the backing store of most file systems are partitions + <braunr> tmpfs has none, it uses the swap space + <mcsim> if we allocate memory for tmpfs using vm_allocate, will it be able + to use swap partition? + <braunr> it should + <braunr> vm_allocate just maps anonymous memory + <braunr> anonymous memory uses swap space as its backing store too + <braunr> but be aware that this part of the vm system is known to have + deficiencies + <braunr> which is why all mach based implementations have rewritten their + default pager + <mcsim> what kind of deficiencies? + <braunr> bugs + <braunr> and design issues, making anonymous memory fragmentation horrible + <antrik> mcsim: vm_allocate doesn't return a memory object; so it can't be + passed to clients for mmap() + <mcsim> antrik: I use vm_allocate in pager_read_page + <antrik> mcsim: well, that means that you have to actually implement a + pager yourself + <antrik> also, when the kernel asks the pager to write back some pages, it + expects the memory to become free. if you are "paging" to ordinary + anonymous memory, this doesn't happen; so I expect it to have a very bad + effect on system performance + <antrik> both can be avoided by just passing a real anonymous memory + object, i.e. one provided by the defpager + <antrik> only problem is that the current defpager implementation can't + really handle that... + <antrik> at least that's my understanding of the situation diff --git a/hurd/virtual_file_system/discussion.mdwn b/hurd/virtual_file_system/discussion.mdwn new file mode 100644 index 00000000..9e12d01e --- /dev/null +++ b/hurd/virtual_file_system/discussion.mdwn @@ -0,0 +1,39 @@ +[[!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_documentation]] + +IRC, freenode, #hurd, 2011-11-12: + + <sea4ever> So hurd implements a 'transparent translator' somewhere which + just passes all IO calls to the posix IO I'm used to? (i.e. read, write, + open, close, etc.?) + <youpi> it's the normal way of operation + <youpi> glibc's read() doesn't do a system call, it always does an RPC to + the underlying translator + <youpi> be it ext2fs for /, or your foobarfs for your node + <sea4ever> Ok that makes sense. How does one program know which translator + it should refer to though? + <sea4ever> the read() call magically knows which process to invoke? + <youpi> the / translator is always known + <youpi> and then you ask /'s translator about /home, then /home/you, then + /home/you/foobar + <youpi> it tells you which other translator tyou have to contact + <youpi> that's on open + <sea4ever> It's a tree! Ok. + <youpi> the notion of fd is then simply knowing the translator + <sea4ever> Right. 'file descriptor' is now 'translator address descriptor' + maybe. + <youpi> it's glibc which knows about FDs, nothing else knows + <youpi> yes + <youpi> actually an RPC port, simply + <sea4ever> I want to try out the new RPC mechanism that mach implements + <youpi> err, which "new" RPC ? + <youpi> mach's RPCs are very old actually :) |