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author | Konstantin Belousov <kib@FreeBSD.org> | 2010-09-05 14:47:46 +0000 |
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committer | Konstantin Belousov <kib@FreeBSD.org> | 2010-09-05 14:47:46 +0000 |
commit | 5e9cd1dbf8adbeddcedf697245d16430fb3bf569 (patch) | |
tree | 0c10e013302ef00dcdb95418fca3599c58f5373e | |
parent | 52129fcd7847f076a686c829a6410a89c78ac41b (diff) | |
download | src-5e9cd1dbf8adbeddcedf697245d16430fb3bf569.tar.gz src-5e9cd1dbf8adbeddcedf697245d16430fb3bf569.zip |
Document MAKEDEV_ETERNAL.
MFC after: 3 days
Notes
Notes:
svn path=/head/; revision=212233
-rw-r--r-- | share/man/man9/make_dev.9 | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/share/man/man9/make_dev.9 b/share/man/man9/make_dev.9 index 7faedaa43925..9cc755f5a95a 100644 --- a/share/man/man9/make_dev.9 +++ b/share/man/man9/make_dev.9 @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd May 6, 2010 +.Dd September 5, 2010 .Dt MAKE_DEV 9 .Os .Sh NAME @@ -135,6 +135,7 @@ The following values are currently accepted: MAKEDEV_REF reference the created device MAKEDEV_NOWAIT do not sleep, may return NULL MAKEDEV_WAITOK allow the function to sleep to satisfy malloc +MAKEDEV_ETERNAL created device will be never destroyed .Ed .Pp The @@ -154,6 +155,18 @@ the device created is destroyed immediately after drops his reference to cdev. .Pp The +.Dv MAKEDEV_ETERNAL +flag allows the kernel to not acquire some locks when translating system +calls into the cdevsw methods calls. +It is responsibility of the driver author to make sure that +.Fn destroy_dev +is never called on the returned cdev. +For the convenience, use the +.Dv MAKEDEV_ETERNAL_KLD +flag for the code that can be compiled into kernel or loaded +(and unloaded) as loadable module. +.Pp +The .Fn make_dev_cred function is equivalent to the call .Bd -literal -offset indent |