Bug 23872
| Summary: | epoll_create(0) fails. Mismatch between implementation and manpage | ||
|---|---|---|---|
| Product: | Documentation | Reporter: | Joern Heissler (kernelbugs) |
| Component: | man-pages | Assignee: | Michael Kerrisk (mtk.manpages) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | normal | CC: | mtk.manpages, pebolle |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 2.6.36 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
Thanks for this report Joern. Of course, the right change here is to fix the documentation. I applied this patch for man-pages-3.22: --- a/man2/epoll_create.2 +++ b/man2/epoll_create.2 @@ -44,7 +44,7 @@ is not the maximum size of the backing store but just a hint to the kernel about how to dimension internal structures. (Nowadays, .I size -is ignored; see NOTES below.) +is unused; see NOTES below.) .BR epoll_create () returns a file descriptor referring to the new epoll instance. @@ -118,7 +118,7 @@ is Linux-specific, and was introduced in kernel 2.5.44. .SH NOTES Since Linux 2.6.8, the .I size -argument is unused. +argument is unused, but must be greater than zero. (The kernel dynamically sizes the required data structures without needing this initial hint.) .SH "SEE ALSO" (In reply to comment #1) > I applied this patch for man-pages-3.22: 0) That actually was man-pages-3.32. 1) This bug can be CLOSED (and set to FIXED, I assume). |
The epoll_create manpage (current version as of 2010-11-28) contains: SYNOPSIS ... int epoll_create(int size); ... DESCRIPTION ... (Nowadays, size is ignored; see NOTES below.) ... ERRORS EINVAL size is not positive. ... NOTES Since Linux 2.6.8, the size argument is unused. ... on the other hand, fs/eventpoll.c contains: SYSCALL_DEFINE1(epoll_create, int, size) { if (size <= 0) return -EINVAL; return sys_epoll_create1(0); } The size parameter is not ignored as stated in the manpage. Please correct the manpage or remove the check inside the implementation.