From: Roman Penyaev <rpenyaev@suse.de>
To: unlisted-recipients:; (no To-header on input)
Cc: Roman Penyaev <rpenyaev@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Davidlohr Bueso <dbueso@suse.de>, Jason Baron <jbaron@akamai.com>,
Al Viro <viro@zeniv.linux.org.uk>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrea Parri <andrea.parri@amarulasolutions.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH v2 02/13] epoll: introduce user structures for polling from userspace
Date: Mon, 21 Jan 2019 21:14:45 +0100 [thread overview]
Message-ID: <20190121201456.28338-3-rpenyaev@suse.de> (raw)
In-Reply-To: <20190121201456.28338-1-rpenyaev@suse.de>
This one introduces structures of user items array:
struct user_epheader -
describes inserted epoll items.
struct user_epitem -
single epoll item, visible to userspace.
Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
fs/eventpoll.c | 9 +++++++++
include/uapi/linux/eventpoll.h | 19 +++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 2cc183e86a29..f598442512f3 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -9,6 +9,8 @@
*
* Davide Libenzi <davidel@xmailserver.org>
*
+ * Polling from userspace support by Roman Penyaev <rpenyaev@suse.de>
+ * (C) Copyright 2019 SUSE, All Rights Reserved
*/
#include <linux/init.h>
@@ -109,6 +111,13 @@
#define EP_ITEM_COST (sizeof(struct epitem) + sizeof(struct eppoll_entry))
+/*
+ * That is around 1.3mb of allocated memory for one epfd. What is more
+ * important is ->index_length, which should be ^2, so do not increase
+ * max items number to avoid size doubling of user index.
+ */
+#define EP_USERPOLL_MAX_ITEMS_NR 65536
+
struct epoll_filefd {
struct file *file;
int fd;
diff --git a/include/uapi/linux/eventpoll.h b/include/uapi/linux/eventpoll.h
index 39dfc29f0f52..690a625ddeb2 100644
--- a/include/uapi/linux/eventpoll.h
+++ b/include/uapi/linux/eventpoll.h
@@ -79,4 +79,23 @@ struct epoll_event {
__u64 data;
} EPOLL_PACKED;
+struct epoll_uitem {
+ __poll_t ready_events;
+ struct epoll_event event;
+};
+
+#define EPOLL_USERPOLL_HEADER_SIZE 128
+#define EPOLL_USERPOLL_HEADER_MAGIC 0xeb01eb01
+
+struct epoll_uheader {
+ u32 magic; /* epoll user header magic */
+ u32 header_length; /* length of the header + items */
+ u32 index_length; /* length of the index ring, always pow2 */
+ u32 max_items_nr; /* max number of items */
+ u32 head; /* updated by userland */
+ u32 tail; /* updated by kernel */
+
+ struct epoll_uitem items[] __aligned(EPOLL_USERPOLL_HEADER_SIZE);
+};
+
#endif /* _UAPI_LINUX_EVENTPOLL_H */
--
2.19.1
next prev parent reply other threads:[~2019-01-21 20:15 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 20:14 [RFC PATCH v2 00/13] epoll: support pollable epoll from userspace Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 01/13] epoll: move private helpers from a header to the source Roman Penyaev
2019-01-21 20:14 ` Roman Penyaev [this message]
2019-01-21 21:34 ` [RFC PATCH v2 02/13] epoll: introduce user structures for polling from userspace Linus Torvalds
2019-01-22 11:46 ` Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 03/13] epoll: allocate user header and user events ring " Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 04/13] epoll: some sanity flags checks for epoll syscalls " Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 05/13] epoll: offload polling to a work in case of epfd polled " Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 06/13] epoll: introduce helpers for adding/removing events to uring Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 07/13] epoll: call ep_add_event_to_uring() from ep_poll_callback() Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 08/13] epoll: support polling from userspace for ep_insert() Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 09/13] epoll: support polling from userspace for ep_remove() Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 10/13] epoll: support polling from userspace for ep_modify() Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 11/13] epoll: support polling from userspace for ep_poll() Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 12/13] epoll: support mapping for epfd when polled from userspace Roman Penyaev
2019-01-21 20:14 ` [RFC PATCH v2 13/13] epoll: implement epoll_create2() syscall Roman Penyaev
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190121201456.28338-3-rpenyaev@suse.de \
--to=rpenyaev@suse.de \
--cc=akpm@linux-foundation.org \
--cc=andrea.parri@amarulasolutions.com \
--cc=dbueso@suse.de \
--cc=jbaron@akamai.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).