TTY, devpts: document pty count limiting
Subsystems (2)
PATCH 1/1 TTY, devpts: document pty count limiting
Logic was changed in kernel 3.4 by commit e9aba5158a80 ("tty: rework pty count limiting") but still isn't documented. Better late than never.
--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)
Documentation/filesystems/devpts.txt +9 -0
@@ -51,6 +51,15 @@ where 'ns_exec -cm /bin/bash' calls clone() with CLONE_NEWNS flag and execs /bin/bash in the child process. A pty created by the sshd is not visible in the original mount of /dev/pts. +Total count of pty pairs in all instances is limited by sysctls: +kernel.pty.max = 4096 - global limit +kernel.pty.reserve = 1024 - reserve for initial instance +kernel.pty.nr - current count of ptys + +Per-instance limit could be set by adding mount option "max=<count>". +This feature was added in kernel 3.4 together with sysctl kernel.pty.reserve. +In kernels older than 3.4 sysctl kernel.pty.max works as per-instance limit. + User-space changes ------------------
Documentation/sysctl/kernel.txt +7 -0
@@ -63,6 +63,7 @@ show up in /proc/sys/kernel: - printk_delay - printk_ratelimit - printk_ratelimit_burst +- pty/ - randomize_va_space - real-root-dev ==> Documentation/initrd.txt - reboot-cmd [ SPARC only ]
@@ -683,6 +684,12 @@ send before ratelimiting kicks in. ============================================================== +pty/: + +See Documentation/filesystems/devpts.txt. + +============================================================== + randomize_va_space: This option can be used to select the type of process address
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)
Any reason you didn't cc: the tty maintainer on this?
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)
Any reason you didn't cc: the tty maintainer on this?
Quoted 11 lines · Greg KH
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)Any reason you didn't cc: the tty maintainer on this?
It looks like he attempted to and managed to get your old suse.de address.
Eric
Quoted 11 lines · Greg KH
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)Any reason you didn't cc: the tty maintainer on this?
It looks like he attempted to and managed to get your old suse.de address.
Eric
Quoted 12 lines · Eric W. Biederman
Quoted 10 lines · Greg KH
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)
Quoted 4 lines
Quoted 1 line
Any reason you didn't cc: the tty maintainer on this?
It looks like he attempted to and managed to get your old suse.de address.
Ah, you are right, my apologies, that address is long dead :)
greg k-h
Quoted 12 lines · Eric W. Biederman
Quoted 10 lines · Greg KH
Quoted 8 lines · Konstantin Khlebnikov
Logic was changed in kernel 3.4 by commit
e9aba5158a80("tty: rework pty count limiting") but still isn't documented. Better late than never.Signed-off-by Konstantin Khlebnikov <[email protected]>--- Documentation/filesystems/devpts.txt | 9 +++++++++ Documentation/sysctl/kernel.txt | 7 +++++++ 2 files changed, 16 insertions(+)
Quoted 4 lines
Quoted 1 line
Any reason you didn't cc: the tty maintainer on this?
It looks like he attempted to and managed to get your old suse.de address.
Ah, you are right, my apologies, that address is long dead :)
greg k-h