Messages in this thread Patch in this message | | | Date | Fri, 19 Aug 2005 23:14:39 -0400 | From | Chuck Ebbert <> | Subject | [patch 2.6.13-rc6] docs: fix misinformation about overcommit_memory |
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Someone complained about the docs for vm_overcommit_memory being wrong. This patch copies the text from the vm documentation into procfs. Please apply.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Documentation/filesystems/proc.txt | 29 +++++++++++++++++++---------- 1 files changed, 19 insertions(+), 10 deletions(-)
--- 2.6.13-rc6c.orig/Documentation/filesystems/proc.txt +++ 2.6.13-rc6c/Documentation/filesystems/proc.txt @@ -1240,16 +1240,25 @@ swap-intensive. overcommit_memory ----------------- -This file contains one value. The following algorithm is used to decide if -there's enough memory: if the value of overcommit_memory is positive, then -there's always enough memory. This is a useful feature, since programs often -malloc() huge amounts of memory 'just in case', while they only use a small -part of it. Leaving this value at 0 will lead to the failure of such a huge -malloc(), when in fact the system has enough memory for the program to run. - -On the other hand, enabling this feature can cause you to run out of memory -and thrash the system to death, so large and/or important servers will want to -set this value to 0. +Controls overcommit of system memory: + +0 - Heuristic overcommit handling. Obvious overcommits of + address space are refused. Used for a typical system. It + ensures a seriously wild allocation fails while allowing + overcommit to reduce swap usage. root is allowed to + allocate slighly more memory in this mode. This is the + default. + +1 - Always overcommit. Appropriate for some scientific + applications. + +2 - Don't overcommit. The total address space commit + for the system is not permitted to exceed swap + a + configurable percentage (default is 50) of physical RAM. + Depending on the percentage you use, in most situations + this means a process will not be killed while accessing + pages but will receive errors on memory allocation as + appropriate. nr_hugepages and hugetlb_shm_group ---------------------------------- __ Chuck - 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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