Messages in this thread Patch in this message | | | Date | Sun, 1 Feb 2009 14:43:50 +1300 | Subject | Re: [patch] drop epoll max_user_instances and rely only on max_user_watches | From | Michael Kerrisk <> |
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Hi Davide,
On Sun, Feb 1, 2009 at 2:30 PM, Davide Libenzi <davidel@xmailserver.org> wrote: > On Sun, 1 Feb 2009, Michael Kerrisk wrote: > >> Hi Davide, >> >> On Fri, Jan 30, 2009 at 7:54 AM, Davide Libenzi <davidel@xmailserver.org> wrote: >> > On Thu, 29 Jan 2009, Michael Kerrisk wrote: >> > >> >> Since max_user_instances was added in 2.6.28, and this is an ABI >> >> change, I suggest this should go into .29-rc, so that >> >> max_user_instances spends as little time in the wild as possible. >> > >> > Agreed, like I already told Andrew. Sorry Michael for the double change to >> > the man page :/ >> >> So is the right change to the epoll(7) page (see >> http://www.kernel.org/doc/man-pages/online/pages/man7/epoll.7.html ) >> to simply remive the text on max_user_instances: >> >> /proc/sys/fs/epoll/max_user_instances (since Linux 2.6.28) >> This specifies an upper limit on the number of epoll >> instances that can be created per real user ID. >> >> Or are other changes also required? > > Yes. Plus, max_user_watches, instead of being 1/32 of lowmem, it's 4%. > Just a detail.
Would you please review the following patch, which comments out the text for max_user_instances, and updates the numbers for max_user-watches.
Cheers,
Michael
diff --git a/man7/epoll.7 b/man7/epoll.7 index 7c67e13..6ee686e 100644 --- a/man7/epoll.7 +++ b/man7/epoll.7 @@ -172,10 +172,11 @@ with .SS /proc interfaces The following interfaces can be used to limit the amount of kernel memory consumed by epoll: -.TP -.IR /proc/sys/fs/epoll/max_user_instances " (since Linux 2.6.28)" -This specifies an upper limit on the number of epoll instances -that can be created per real user ID. +.\" Following was added in 2.6.28, but them removed in 2.6.29 +.\" .TP +.\" .IR /proc/sys/fs/epoll/max_user_instances " (since Linux 2.6.28)" +.\" This specifies an upper limit on the number of epoll instances +.\" that can be created per real user ID. .TP .IR /proc/sys/fs/epoll/max_user_watches " (since Linux 2.6.28)" This specifies a limit on the total number of @@ -185,10 +186,10 @@ The limit is per real user ID. Each registered file descriptor costs roughly 90 bytes on a 32-bit kernel, and roughly 160 bytes on a 64-bit kernel. Currently, -.\" 2.6.28 +.\" 2.6.29 (in 2.6.28, the default was 1/32 of lowmem) the default value for .I max_user_watches -is 1/32 of the available low memory, +is 1/25 (4%) of the available low memory, divided by the registration cost in bytes. .SS Example for Suggested Usage While the usage of
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