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| author | kib <kib@FreeBSD.org> | 2016-09-25 17:24:10 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2016-09-25 17:24:10 +0000 |
| commit | 7ed6c1bd4b4f838ddb1d2c41ab8a9fa8fa083832 (patch) | |
| tree | 6b8cb78b25709e6b2894b9a87432e75a9505c123 /share | |
| parent | b857ade1bc9135f147ed79a9a87bc32f27084c19 (diff) | |
| download | FreeBSD-src-7ed6c1bd4b4f838ddb1d2c41ab8a9fa8fa083832.zip FreeBSD-src-7ed6c1bd4b4f838ddb1d2c41ab8a9fa8fa083832.tar.gz | |
MFC r305692:
Add FPU_KERN_NOCTX flag to the fpu_kern_enter() function on amd64.
Diffstat (limited to 'share')
| -rw-r--r-- | share/man/man9/fpu_kern.9 | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/share/man/man9/fpu_kern.9 b/share/man/man9/fpu_kern.9 index 92204d2..378362f 100644 --- a/share/man/man9/fpu_kern.9 +++ b/share/man/man9/fpu_kern.9 @@ -120,6 +120,16 @@ could be used from both kernel thread and syscall contexts. The .Fn fpu_kern_leave function correctly handles such contexts. +.It Dv FPU_KERN_NOCTX +Avoid nesting save area. +If the flag is specified, the +.Fa ctx +must be passed as +.Va NULL . +The flag should only be used for really short code blocks +which can be executed in a critical section. +It avoids the need to allocate the FPU context by the cost +of increased system latency. .El .El .Pp |
