linux/Documentation/sysctl, branch v2.6.20

[PATCH] x86: add sysctl for kstack_depth_to_print

2006-12-07T01:14:11Z

Add sysctl for kstack_depth_to_print. This lets users change the amount of raw stack data printed in dump_stack() without having to reboot. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen

Fix typos in /Documentation : Misc

2006-11-30T04:21:10Z

This patch fixes typos in various Documentation txts. The patch addresses some misc words. Signed-off-by: Matt LaPlante Acked-by: Randy Dunlap Signed-off-by: Adrian Bunk

[PATCH] document the core-dump-to-a-pipe patch

2006-10-11T18:14:22Z

The pipe-a-coredump-to-a-program feature was undocumented. *Grumble*. NB: a good enhancement to that patch would be: save all the stuff that a core file can get from the %x expansions in the environment. Signed-off-by: Matthias Urlichs Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] zone_reclaim: dynamic slab reclaim

2006-09-26T15:48:51Z

Currently one can enable slab reclaim by setting an explicit option in /proc/sys/vm/zone_reclaim_mode. Slab reclaim is then used as a final option if the freeing of unmapped file backed pages is not enough to free enough pages to allow a local allocation. However, that means that the slab can grow excessively and that most memory of a node may be used by slabs. We have had a case where a machine with 46GB of memory was using 40-42GB for slab. Zone reclaim was effective in dealing with pagecache pages. However, slab reclaim was only done during global reclaim (which is a bit rare on NUMA systems). This patch implements slab reclaim during zone reclaim. Zone reclaim occurs if there is a danger of an off node allocation. At that point we 1. Shrink the per node page cache if the number of pagecache pages is more than min_unmapped_ratio percent of pages in a zone. 2. Shrink the slab cache if the number of the nodes reclaimable slab pages (patch depends on earlier one that implements that counter) are more than min_slab_ratio (a new /proc/sys/vm tunable). The shrinking of the slab cache is a bit problematic since it is not node specific. So we simply calculate what point in the slab we want to reach (current per node slab use minus the number of pages that neeed to be allocated) and then repeately run the global reclaim until that is unsuccessful or we have reached the limit. I hope we will have zone based slab reclaim at some point which will make that easier. The default for the min_slab_ratio is 5% Also remove the slab option from /proc/sys/vm/zone_reclaim_mode. [akpm@osdl.org: cleanups] Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix docs for fs.suid_dumpable

2006-08-27T18:01:28Z

Sergey Vlasov noticed that there is not kernel.suid_dumpable, but fs.suid_dumpable. How KERN_SETUID_DUMPABLE ended up in fs_table[]? Hell knows... Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] doc: update panic_on_oops documentation

2006-08-06T15:57:47Z

Signed-off-by: Maxime Bizon Acked-by: Simon Horman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] ZVC/zone_reclaim: Leave 1% of unmapped pagecache pages for file I/O

2006-07-03T22:26:59Z

It turns out that it is advantageous to leave a small portion of unmapped file backed pages if all of a zone's pages (or almost all pages) are allocated and so the page allocator has to go off-node. This allows recently used file I/O buffers to stay on the node and reduces the times that zone reclaim is invoked if file I/O occurs when we run out of memory in a zone. The problem is that zone reclaim runs too frequently when the page cache is used for file I/O (read write and therefore unmapped pages!) alone and we have almost all pages of the zone allocated. Zone reclaim may remove 32 unmapped pages. File I/O will use these pages for the next read/write requests and the unmapped pages increase. After the zone has filled up again zone reclaim will remove it again after only 32 pages. This cycle is too inefficient and there are potentially too many zone reclaim cycles. With the 1% boundary we may still remove all unmapped pages for file I/O in zone reclaim pass. However. it will take a large number of read and writes to get back to 1% again where we trigger zone reclaim again. The zone reclaim 2.6.16/17 does not show this behavior because we have a 30 second timeout. [akpm@osdl.org: rename the /proc file and the variable] Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] zoned vm counters: zone_reclaim: remove /proc/sys/vm/zone_reclaim_interval

2006-06-30T18:25:35Z

The zone_reclaim_interval was necessary because we were not able to determine how many unmapped pages exist in a zone. Therefore we had to scan in intervals to figure out if any pages were unmapped. With the zoned counters and NR_ANON_PAGES we now know the number of pagecache pages and the number of mapped pages in a zone. So we can simply skip the reclaim if there is an insufficient number of unmapped pages. We use SWAP_CLUSTER_MAX as the boundary. Drop all support for /proc/sys/vm/zone_reclaim_interval. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] support for panic at OOM

2006-06-23T14:42:47Z

This patch adds panic_on_oom sysctl under sys.vm. When sysctl vm.panic_on_oom = 1, the kernel panics intead of killing rogue processes. And if vm.panic_on_oom is 0 the kernel will do oom_kill() in the same way as it does today. Of course, the default value is 0 and only root can modifies it. In general, oom_killer works well and kill rogue processes. So the whole system can survive. But there are environments where panic is preferable rather than kill some processes. Signed-off-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] suspend-to-ram: allow video options to be set at runtime

2006-02-21T04:00:10Z

Currently, acpi video options can only be set on kernel command line. That's little inflexible; I'd like userland s2ram application that just works, and modifying kernel command line according to whitelist is not fun. It is better to just allow s2ram application to set video options just before suspend (according to the whitelist). This implements sysctl to allow setting suspend video options without reboot. (akpm: Documentation updates for this new sysctl are pending..) Signed-off-by: Pavel Machek Cc: "Brown, Len" Cc: "Antonino A. Daplas" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds