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Diffstat (limited to 'FAQ.in')
| -rw-r--r-- | FAQ.in | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/FAQ.in b/FAQ.in index c15611d672..0da19611cc 100644 --- a/FAQ.in +++ b/FAQ.in @@ -776,6 +776,33 @@ If you need nscd, you have to use a 2.1 kernel. Note that I have at this point no information about any other platform. +?? I need lots of open files. What do I have to do? + +{AJ} This is at first a kernel issue. The kernel defines limits with +OPEN_MAX the number of simultaneous open files and with FD_SETSIZE the +number of used file descriptors. You need to change these values in your +kernel and recompile the kernel so that the kernel allows to use more open +files. You don't necessarily need to recompile the GNU C library since the +only place where OPEN_MAX and FD_SETSIZE is really needed in the library +itself is the size of fd_set which is used by select. + +The GNU C library is now (nearly) select free. This means it internally has +no limits imposed by the `fd_set' type. Instead almost all places where the +functionality is needed the `poll' function is used. + +If you increase the number of file descriptors in the kernel you don't need +to recompile the C library. The remaining select calls are in the RPC code. +If your RPC daemons don't need more than FD_SETSIZE file descriptors, you +don't need to change anything at all. + +{UD} You can always get the maximum number of file descriptors a process is +allowed to have open at any time using + + number = sysconf (_SC_OPEN_MAX); + +This will work even if the kernel limits change. + + ? Source and binary incompatibilities, and what to do about them ?? I expect GNU libc to be 100% source code compatible with |