diff mbox series

[man-pages,v2,2/4] madvise.2: document reliable probe for advice support

Message ID 20221018235051.152548-3-zokeefe@google.com (mailing list archive)
State New
Headers show
Series Add MADV_COLLAPSE documentation | expand

Commit Message

Zach O'Keefe Oct. 18, 2022, 11:50 p.m. UTC 
From: Zach O'Keefe <zokeefe@google.com>

EINVAL is an overloaded error code for madvise(2) and it's not clear
under what context it means "advice is not valid" vs another error.

Explicitly document that madvise(0, 0, advice) can reliably be used to
probe for kernel support for "advice", returning zero iff "advice" is
supported by the kernel.

Signed-off-by: Zach O'Keefe <zokeefe@google.com>
---
 man2/madvise.2 | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/man2/madvise.2 b/man2/madvise.2
index 64f788ace..df3413cc8 100644
--- a/man2/madvise.2
+++ b/man2/madvise.2
@@ -790,6 +790,11 @@  that are not mapped, the Linux version of
 ignores them and applies the call to the rest (but returns
 .B ENOMEM
 from the system call, as it should).
+.PP
+.IR madvise(0,\ 0,\ advice)
+will return zero iff
+.I advice
+is supported by the kernel and can be relied on to probe for support.
 .\" .SH HISTORY
 .\" The
 .\" .BR madvise ()