When TTY_NO_WRITE_SPLIT is set and 64 KiB chunks are used, allow
vmalloc() fallback. Supply __GFP_RETRY_MAYFAIL to make kmalloc()
preferable over vmalloc() since we may want a better performance.
Note, both current users copy data to another buffer anyway, so
the type of our allocation doesn't affect their expectations.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/tty/tty_io.c | 9 +++------
drivers/usb/class/cdc-acm.c | 4 ----
2 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 6616d4a0d41d..8fedfe88dff7 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -170,7 +170,7 @@ static void free_tty_struct(struct tty_struct *tty)
{
tty_ldisc_deinit(tty);
put_device(tty->dev);
- kfree(tty->write_buf);
+ kvfree(tty->write_buf);
tty->magic = 0xDEADDEAD;
kfree(tty);
}
@@ -997,9 +997,6 @@ static inline ssize_t do_tty_write(
* layer has problems with bigger chunks. It will
* claim to be able to handle more characters than
* it actually does.
- *
- * FIXME: This can probably go away now except that 64K chunks
- * are too likely to fail unless switched to vmalloc...
*/
chunk = 2048;
if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
@@ -1014,12 +1011,12 @@ static inline ssize_t do_tty_write(
if (chunk < 1024)
chunk = 1024;
- buf_chunk = kmalloc(chunk, GFP_KERNEL);
+ buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!buf_chunk) {
ret = -ENOMEM;
goto out;
}
- kfree(tty->write_buf);
+ kvfree(tty->write_buf);
tty->write_cnt = chunk;
tty->write_buf = buf_chunk;
}
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index b3ce7338cb6b..9b9aea24d58c 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -685,10 +685,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
if (retval)
goto error_get_interface;
- /*
- * FIXME: Why do we need this? Allocating 64K of physically contiguous
- * memory is really nasty...
- */
set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
acm->control->needs_remote_wakeup = 1;
--
2.34.1
