diff options
Diffstat (limited to 'open_issues/performance')
| -rw-r--r-- | open_issues/performance/degradation.mdwn | 16 | ||||
| -rw-r--r-- | open_issues/performance/io_system/clustered_page_faults.mdwn | 23 | ||||
| -rw-r--r-- | open_issues/performance/ipc_virtual_copy.mdwn | 37 |
3 files changed, 72 insertions, 4 deletions
diff --git a/open_issues/performance/degradation.mdwn b/open_issues/performance/degradation.mdwn index db759308..8c9a087c 100644 --- a/open_issues/performance/degradation.mdwn +++ b/open_issues/performance/degradation.mdwn @@ -10,8 +10,12 @@ License|/fdl]]."]]"""]] [[!meta title="Degradation of GNU/Hurd ``system performance''"]] -Email, *id:"87mxg2ahh8.fsf@kepler.schwinge.homeip.net"* (bug-hurd, 2011-07-25, -Thomas Schwinge) +[[!tag open_issue_gnumach open_issue_hurd]] + +[[!toc]] + + +# Email, `id:"87mxg2ahh8.fsf@kepler.schwinge.homeip.net"` (bug-hurd, 2011-07-25, Thomas Schwinge) > Building a certain GCC configuration on a freshly booted system: 11 h. > Remove build tree, build it again (2nd): 12 h 50 min. Huh. Remove build @@ -27,9 +31,8 @@ IRC, freenode, #hurd, 2011-07-23: are some serious fragmentation issues < braunr> antrik: both could be induced by fragmentation ---- -During [[IPC_virtual_copy]] testing: +# During [[IPC_virtual_copy]] testing IRC, freenode, #hurd, 2011-09-02: @@ -38,3 +41,8 @@ IRC, freenode, #hurd, 2011-09-02: 800 fifteen minutes ago) <braunr> manuel: i observed the same behaviour [...] + + +# IRC, freenode, #hurd, 2011-09-22 + +See [[/open_issues/pagers]], IRC, freenode, #hurd, 2011-09-22. diff --git a/open_issues/performance/io_system/clustered_page_faults.mdwn b/open_issues/performance/io_system/clustered_page_faults.mdwn index 9e20f8e1..a3baf30d 100644 --- a/open_issues/performance/io_system/clustered_page_faults.mdwn +++ b/open_issues/performance/io_system/clustered_page_faults.mdwn @@ -137,3 +137,26 @@ License|/fdl]]."]]"""]] where the pager interface needs to be modified, not the Mach one?... <braunr> antrik: would be nice wouldn't it ? :) <braunr> antrik: more probably the page fault handler + + +# IRC, freenode, #hurd, 2011-09-28 + + <slpz> antrik: I've just recovered part of my old multipage I/O work + <slpz> antrik: I intend to clean and submit it after finishing the changes + to the pageout system. + <antrik> slpz: oh, great! + <antrik> didn't know you worked on multipage I/O + <antrik> slpz: BTW, have you checked whether any of the work done for GSoC + last year is any good?... + <antrik> (apart from missing copyright assignments, which would be a + serious problem for the Hurd parts...) + <slpz> antrik: It was seven years ago, but I did: + http://www.mail-archive.com/bug-hurd@gnu.org/msg10285.html :-) + <slpz> antrik: Sincerely, I don't think the quality of that code is good + enough to be considered... but I think it was my fault as his mentor for + not correcting him soon enough... + <antrik> slpz: I see + <antrik> TBH, I feel guilty myself, for not asking about the situation + immediately when he stopped attending meetings... + <antrik> slpz: oh, you even already looked into vm_pageout_scan() back then + :-) diff --git a/open_issues/performance/ipc_virtual_copy.mdwn b/open_issues/performance/ipc_virtual_copy.mdwn index 00fa7180..9708ab96 100644 --- a/open_issues/performance/ipc_virtual_copy.mdwn +++ b/open_issues/performance/ipc_virtual_copy.mdwn @@ -356,3 +356,40 @@ IRC, freenode, #hurd, 2011-09-06: <youpi> in PV it does not make sense: the guest already provides the translated page table <youpi> which is just faster than anything else + +IRC, freenode, #hurd, 2011-09-09: + + <antrik> oh BTW, for another data point: dd zero->null gets around 225 MB/s + on my lowly 1 GHz Pentium3, with a blocksize of 32k + <antrik> (but only half of that with 256k blocksize, and even less with 1M) + <antrik> the system has been up for a while... don't know whether it's + faster on a freshly booted one + +IRC, freenode, #hurd, 2011-09-15: + + <sudoman> + http://www.reddit.com/r/gnu/comments/k68mb/how_intelamd_inadvertently_fixed_gnu_hurd/ + <sudoman> so is the dd command pointed to by that article a measure of io + performance? + <antrik> sudoman: no, not really + <antrik> it's basically the baseline of what is possible -- but the actual + slowness we experience is more due to very unoptimal disk access patterns + <antrik> though using KVM with writeback caching does actually help with + that... + <antrik> also note that the title of this post really makes no + sense... nested page tables should provide similar improvements for *any* + guest system doing VM manipulation -- it's not Hurd-specific at all + <sudoman> ok, that makes sense. thanks :) + +IRC, freenode, #hurd, 2011-09-16: + + <slpz> antrik: I wrote that article (the one about How AMD/Intel fixed...) + <slpz> antrik: It's obviously a bit of an exaggeration, but it's true that + nested pages supposes a great improvement in the performance of Hurd + running on virtual machines + <slpz> antrik: and it's Hurd specific, as this system is more affected by + the cost of page faults + <slpz> antrik: and as the impact of virtualization on the performance is + much higher than (almost) any other OS. + <slpz> antrik: also, dd from /dev/zero to /dev/null it's a measure on how + fast OOL IPC is. |