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| author | Dmitry Safonov <dima@arista.com> | 2018-11-01 01:24:48 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 12:16:33 +0100 |
| commit | c96cf923a98d1b094df9f0cf97a83e118817e31b (patch) | |
| tree | 600f4d868ef87ff58a642bb7e6d4825894d9c657 /Documentation | |
| parent | tty: Hold tty_ldisc_lock() during tty_reopen() (diff) | |
| download | linux-c96cf923a98d1b094df9f0cf97a83e118817e31b.tar.xz linux-c96cf923a98d1b094df9f0cf97a83e118817e31b.zip | |
tty: Don't block on IO when ldisc change is pending
There might be situations where tty_ldisc_lock() has blocked, but there
is already IO on tty and it prevents line discipline changes.
It might theoretically turn into dead-lock.
Basically, provide more priority to pending tty_ldisc_lock() than to
servicing reads/writes over tty.
User-visible issue was reported by Mikulas where on pa-risc with
Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper
locking in tty_reopen().
Cc: Jiri Slaby <jslaby@suse.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions