From: Christoph Hellwig <hch@lst.de>
To: viro@zeniv.linux.org.uk
Cc: Avi Kivity <avi@scylladb.com>,
linux-aio@kvack.org, linux-fsdevel@vger.kernel.org,
netdev@vger.kernel.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 30/30] random: convert to ->poll_mask
Date: Wed, 28 Mar 2018 09:29:26 +0200 [thread overview]
Message-ID: <20180328072926.17131-31-hch@lst.de> (raw)
In-Reply-To: <20180328072926.17131-1-hch@lst.de>
The big change is that random_read_wait and random_write_wait are merged
into a single waitqueue that uses keyed wakeups. Because wait_event_*
doesn't know about that this will lead to occassional spurious wakeups
in _random_read and add_hwgenerator_randomness, but wait_event_* is
designed to handle these and were are not in a a hot path there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/char/random.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/drivers/char/random.c b/drivers/char/random.c
index e5b3d3ba4660..840d80b64431 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -401,8 +401,7 @@ static struct poolinfo {
/*
* Static global variables
*/
-static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
-static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
+static DECLARE_WAIT_QUEUE_HEAD(random_wait);
static struct fasync_struct *fasync;
static DEFINE_SPINLOCK(random_ready_list_lock);
@@ -710,7 +709,7 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
/* should we wake readers? */
if (entropy_bits >= random_read_wakeup_bits) {
- wake_up_interruptible(&random_read_wait);
+ wake_up_interruptible_poll(&random_wait, POLLIN);
kill_fasync(&fasync, SIGIO, POLL_IN);
}
/* If the input pool is getting full, send some
@@ -1293,7 +1292,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
trace_debit_entropy(r->name, 8 * ibytes);
if (ibytes &&
(r->entropy_count >> ENTROPY_SHIFT) < random_write_wakeup_bits) {
- wake_up_interruptible(&random_write_wait);
+ wake_up_interruptible_poll(&random_wait, POLLOUT);
kill_fasync(&fasync, SIGIO, POLL_OUT);
}
@@ -1748,7 +1747,7 @@ _random_read(int nonblock, char __user *buf, size_t nbytes)
if (nonblock)
return -EAGAIN;
- wait_event_interruptible(random_read_wait,
+ wait_event_interruptible(random_wait,
ENTROPY_BITS(&input_pool) >=
random_read_wakeup_bits);
if (signal_pending(current))
@@ -1784,14 +1783,17 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
return ret;
}
+static struct wait_queue_head *
+random_get_poll_head(struct file *file, __poll_t events)
+{
+ return &random_wait;
+}
+
static __poll_t
-random_poll(struct file *file, poll_table * wait)
+random_poll_mask(struct file *file, __poll_t events)
{
- __poll_t mask;
+ __poll_t mask = 0;
- poll_wait(file, &random_read_wait, wait);
- poll_wait(file, &random_write_wait, wait);
- mask = 0;
if (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits)
mask |= EPOLLIN | EPOLLRDNORM;
if (ENTROPY_BITS(&input_pool) < random_write_wakeup_bits)
@@ -1890,7 +1892,8 @@ static int random_fasync(int fd, struct file *filp, int on)
const struct file_operations random_fops = {
.read = random_read,
.write = random_write,
- .poll = random_poll,
+ .get_poll_head = random_get_poll_head,
+ .poll_mask = random_poll_mask,
.unlocked_ioctl = random_ioctl,
.fasync = random_fasync,
.llseek = noop_llseek,
@@ -2223,7 +2226,7 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
* We'll be woken up again once below random_write_wakeup_thresh,
* or when the calling thread is about to terminate.
*/
- wait_event_interruptible(random_write_wait, kthread_should_stop() ||
+ wait_event_interruptible(random_wait, kthread_should_stop() ||
ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits);
mix_pool_bytes(poolp, buffer, count);
credit_entropy_bits(poolp, entropy);
--
2.14.2
next prev parent reply other threads:[~2018-03-28 7:29 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-28 7:28 aio poll and a new in-kernel poll API V7 Christoph Hellwig
2018-03-28 7:28 ` [PATCH 01/30] fs: unexport poll_schedule_timeout Christoph Hellwig
2018-03-28 7:28 ` [PATCH 02/30] fs: cleanup do_pollfd Christoph Hellwig
2018-03-28 7:28 ` [PATCH 03/30] fs: update documentation to mention __poll_t and match the code Christoph Hellwig
2018-03-28 7:29 ` [PATCH 04/30] fs: add new vfs_poll and file_can_poll helpers Christoph Hellwig
2018-03-28 7:29 ` [PATCH 05/30] fs: introduce new ->get_poll_head and ->poll_mask methods Christoph Hellwig
2018-03-28 7:29 ` [PATCH 06/30] aio: simplify cancellation Christoph Hellwig
2018-03-28 7:29 ` [PATCH 07/30] aio: add delayed cancel support Christoph Hellwig
2018-03-28 16:35 ` Al Viro
2018-03-28 21:34 ` Al Viro
2018-03-29 8:53 ` Christoph Hellwig
2018-03-29 14:25 ` Al Viro
2018-03-29 18:08 ` Christoph Hellwig
2018-03-28 7:29 ` [PATCH 08/30] aio: implement IOCB_CMD_POLL Christoph Hellwig
2018-03-28 7:29 ` [PATCH 09/30] net: refactor socket_poll Christoph Hellwig
2018-03-28 7:29 ` [PATCH 10/30] net: add support for ->poll_mask in proto_ops Christoph Hellwig
2018-03-28 7:29 ` [PATCH 11/30] net: remove sock_no_poll Christoph Hellwig
2018-03-28 7:29 ` [PATCH 12/30] net/tcp: convert to ->poll_mask Christoph Hellwig
2018-03-28 7:29 ` [PATCH 13/30] net/unix: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 14/30] net: convert datagram_poll users tp ->poll_mask Christoph Hellwig
2018-03-28 7:29 ` [PATCH 15/30] net/dccp: convert to ->poll_mask Christoph Hellwig
2018-03-28 7:29 ` [PATCH 16/30] net/atm: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 17/30] net/vmw_vsock: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 18/30] net/tipc: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 19/30] net/sctp: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 20/30] net/bluetooth: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 21/30] net/caif: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 22/30] net/nfc: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 23/30] net/phonet: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 24/30] net/iucv: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 25/30] net/rxrpc: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 26/30] crypto: af_alg: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 27/30] pipe: " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 28/30] eventfd: switch " Christoph Hellwig
2018-03-28 7:29 ` [PATCH 29/30] timerfd: convert " Christoph Hellwig
2018-03-28 7:29 ` Christoph Hellwig [this message]
2018-03-29 20:32 aio poll and a new in-kernel poll API V8 Christoph Hellwig
2018-03-29 20:33 ` [PATCH 30/30] random: convert to ->poll_mask Christoph Hellwig
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