Bug 105997
| Summary: | sys/kern/sys_pipe.c refer to tuning(7), but there is no information about kern.ipc.maxpipekva in tuning(7) | ||
|---|---|---|---|
| Product: | Documentation | Reporter: | Beat Gaetzi <beat> |
| Component: | Books & Articles | Assignee: | Tom Rhodes <trhodes> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Latest | ||
| Hardware: | Any | ||
| OS: | Any | ||
Author: trhodes Date: Sat Jan 24 01:46:46 2009 New Revision: 187661 URL: http://svn.freebsd.org/changeset/base/187661 Log: Add a comment on kern.ipc.maxpipekva. PR: 105997 Reviewed by: keramida Modified: head/share/man/man7/tuning.7 Modified: head/share/man/man7/tuning.7 ============================================================================== --- head/share/man/man7/tuning.7 Sat Jan 24 01:34:22 2009 (r187660) +++ head/share/man/man7/tuning.7 Sat Jan 24 01:46:46 2009 (r187661) @@ -23,7 +23,7 @@ .\" .\" $FreeBSD$ .\" -.Dd November 19, 2007 +.Dd January 23, 2009 .Dt TUNING 7 .Os .Sh NAME @@ -402,6 +402,16 @@ In this document we will only cover the on the system. .Pp The +.Va kern.ipc.maxpipekva +loader tunable is used to set a hard limit on the amount of pageable +address space available. +This value is auto tuned by the system, but may require manual tuning +in a few rare cases. +Increasing this value to a higher setting, such as `25165824' might +improve performance on systems where pageable address space is +quickly exhausted. +.Pp +The .Va kern.ipc.shm_use_phys sysctl defaults to 0 (off) and may be set to 0 (off) or 1 (on). Setting _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org" State Changed From-To: open->patched Comment added to the tuning.7 manual page. Thanks. Responsible Changed From-To: freebsd-doc->trhodes Over to me. State Changed From-To: patched->closed Changes have been merged for awhile now, thanks. |
In sys/kern/sys_pipe.c there is a refer to tuning(7): printf("kern.ipc.maxpipekva exceeded; see tuning(7)\n"); But in share/man/man7/tuning.7 there is no information about this sysctl MIB. Fix: - Remove reference to tuning(7) from sys_pipe.c or - Add a paragraph about kern.ipc.maxpipekva to tuning.7. I found some information about this sysctl MIB in the comments of sys_pipe.c, but I'm not sure if this is usefull: * kern.ipc.maxpipekva - This is a hard limit on the amount of pageable * address space available to us in pipe_map. This value is normally * autotuned, but may also be loader tuned. * * kern.ipc.pipekva - This read-only sysctl tracks the current amount of * memory in use by pipes. * * Based on how large pipekva is relative to maxpipekva, the following * will happen: * * 0% - 50%: * New pipes are given 16K of memory backing, pipes may dynamically * grow to as large as 64K where needed. * 50% - 75%: * New pipes are given 4K (or PAGE_SIZE) of memory backing, * existing pipes may NOT grow. * 75% - 100%: * New pipes are given 4K (or PAGE_SIZE) of memory backing, * existing pipes will be shrunk down to 4K whenever possible.