Messages in this thread | | | Date | Thu, 11 Apr 2002 18:34:43 -0500 | From | Ken Brownfield <> | Subject | Re: vm-33, strongly recommended [Re: [2.4.17/18pre] VM and swap - it's really unusable] |
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This sounds great, but I still have concerns with using -aa, or subsets of same.
How much of the improved behavior that you're seeing is due to the vm-33 tweaks and not pte-highmem, block-highmem, or any of the 100 or so other 2.4.19-pre6aa1 patches?
For production use, I prefer to divert from mainline only with my specific needs (or trivial fixes). Using -aa would introduce a large array of (to me) unknowns. How many of the -aa patches are "ready" for mainline and production? vm is currently being debated on the floor -- but what about pte-highmem and block-highmem? How many of the other patches are as widely tested as the vm patch? For some reason, applying a patch called "00_readahead-got-broken-somewhere-1" doesn't give me the utmost confidence in production. Call it a failed bag check.
While 2.4.x is a stable kernel, it needs to be a working* kernel until 2.5 can sort out these and the vast array of other issues. IMHO. *Admittedly, "working" in this case only applies to larger servers, but it would be quite tragic to delay the spread of Linux to hardware that's been available and used in production for _years_. Maybe 5% of the installed base has relevant hardware, but the benefit to Linux _far_ outstrips that seemingly anemic number. I've probably rehashed that point too much as it is, but...
What I'd like to hear (and what I suspect many admins trying to get higher-end hardware working optimally in a production environment would like to hear) is what specific patches applied to mainline are needed to correct the current VM and I/O issues in the 2.4 tree?
If it's vm, pte-highmem, and block-highmem, that's fine -- and separable from -aa. Otherwise it's difficult to get people to test, use, and provide feedback that isn't polluted by unnecessary variables.
Thanks, -- Ken. ken@irridia.com
On Wed, Apr 10, 2002 at 01:36:09AM +0200, Andrea Arcangeli wrote: | I recommend everybody to never use a 2.4 kernel without first applying | this vm patch: | | ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.19pre5/vm-33.gz | | It applies cleanly to both 2.4.19pre5 and 2.4.19pre6. Andrew splitted it | into orthogonal pieces for easy merging from Marcelo's side (modulo | -rest that is important too but that it's still quite monolithic, but | it's pointless to invest further effort at this time until we are | certain Marcelo will do its job and eventually merge it in mainline): | | ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.19pre5/ | | So far a first part of those patches is been merged into mainline into | pre5 (not any previous kernel, if you've some problem reproducible with | pre4 pre3 pre2 and pre1 or any previous kernel that's not related to the | async flushing changes, I seen a bogus report floating around to Marcelo | about pre1 pointing to the vm changes, it can't be the vm changes if | it's pre[1234]). | | This VM is under heavy stressing for weeks on my SMP highmem machine | with a real life DBMS workload in a real life setup with huge VM | pressure with mem=1024m and 1.2G of shm pushed in swap constantly by the | kernel, performance of the workload is now very good and exactly | reproducible and constant, so I recommend it for all production systems | (both lowmem desktops and highend servers). | | Alternatively you can use the whole -aa patchkit, to get all the other | critical highend features like pte-highmem, highio etc... | | I haven't bugreports pending on the vm patch. | | Thanks, | | Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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