diff options
| -rw-r--r-- | drivers/char/tty_buffer.c | 6 | ||||
| -rw-r--r-- | include/linux/tty.h | 10 |
2 files changed, 14 insertions, 2 deletions
diff --git a/drivers/char/tty_buffer.c b/drivers/char/tty_buffer.c index 66fa4e10d76..f27c4d6d956 100644 --- a/drivers/char/tty_buffer.c +++ b/drivers/char/tty_buffer.c @@ -247,7 +247,8 @@ int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, { int copied = 0; do { - int space = tty_buffer_request_room(tty, size - copied); + int goal = min(size - copied, TTY_BUFFER_PAGE); + int space = tty_buffer_request_room(tty, goal); struct tty_buffer *tb = tty->buf.tail; /* If there is no space then tb may be NULL */ if (unlikely(space == 0)) @@ -283,7 +284,8 @@ int tty_insert_flip_string_flags(struct tty_struct *tty, { int copied = 0; do { - int space = tty_buffer_request_room(tty, size - copied); + int goal = min(size - copied, TTY_BUFFER_PAGE); + int space = tty_buffer_request_room(tty, goal); struct tty_buffer *tb = tty->buf.tail; /* If there is no space then tb may be NULL */ if (unlikely(space == 0)) diff --git a/include/linux/tty.h b/include/linux/tty.h index 6abfcf5b588..d96e5882f12 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -68,6 +68,16 @@ struct tty_buffer { unsigned long data[0]; }; +/* + * We default to dicing tty buffer allocations to this many characters + * in order to avoid multiple page allocations. We assume tty_buffer itself + * is under 256 bytes. See tty_buffer_find for the allocation logic this + * must match + */ + +#define TTY_BUFFER_PAGE ((PAGE_SIZE - 256) / 2) + + struct tty_bufhead { struct delayed_work work; spinlock_t lock; |