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 06/15] epoll: introduce various of helpers for user structure lengths calculations
Date: Wed, 9 Jan 2019 17:40:16 +0100 [thread overview]
Message-ID: <20190109164025.24554-7-rpenyaev@suse.de> (raw)
In-Reply-To: <20190109164025.24554-1-rpenyaev@suse.de>
Helpers for lengths-from-number and number-from-lengths calculations.
Among them:
ep_polled_by_user()
- returns true if epoll was created with EPOLL_USERPOLL
ep_user_ring_events_available()
- returns true if there is something in user ring buffer
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 | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 9ec682b6488f..ae288f62aa4c 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -438,6 +438,65 @@ static void ep_nested_calls_init(struct nested_calls *ncalls)
spin_lock_init(&ncalls->lock);
}
+static inline unsigned int to_items_length(unsigned int nr)
+{
+ struct eventpoll *ep;
+
+ return (sizeof(*ep->user_header) +
+ (nr << ilog2(sizeof(ep->user_header->items[0]))));
+}
+
+static inline unsigned int to_index_length(unsigned int nr)
+{
+ struct eventpoll *ep;
+
+ return nr << ilog2(sizeof(*ep->user_index));
+}
+
+static inline unsigned int to_items_bm_length(unsigned int nr)
+{
+ return ALIGN(nr, 8) >> 3;
+}
+
+static inline unsigned int to_items_nr(unsigned int len)
+{
+ struct eventpoll *ep;
+
+ return (len - sizeof(*ep->user_header)) >>
+ ilog2(sizeof(ep->user_header->items[0]));
+}
+
+static inline unsigned int to_items_bm_nr(unsigned int len)
+{
+ return len << 3;
+}
+
+static inline unsigned int ep_max_items_nr(struct eventpoll *ep)
+{
+ return to_items_nr(ep->header_length);
+}
+
+static inline unsigned int ep_max_index_nr(struct eventpoll *ep)
+{
+ return ep->index_length >> ilog2(sizeof(*ep->user_index));
+}
+
+static inline unsigned int ep_max_items_bm_nr(struct eventpoll *ep)
+{
+ return to_items_bm_nr(ep->items_bm_length);
+}
+
+static inline bool ep_polled_by_user(struct eventpoll *ep)
+{
+ return !!ep->user_header;
+}
+
+static inline bool ep_user_ring_events_available(struct eventpoll *ep)
+{
+ return ep_polled_by_user(ep) &&
+ ep->user_header->head != ep->user_header->tail;
+}
+
/**
* ep_events_available - Checks if ready events might be available.
*
--
2.19.1
next prev parent reply other threads:[~2019-01-09 16:42 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 16:40 [RFC 00/15] epoll: support pollable epoll from userspace Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 01/15] mm/vmalloc: add new 'alignment' field for vm_struct structure Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 02/15] mm/vmalloc: move common logic from __vmalloc_area_node to a separate func Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 03/15] mm/vmalloc: introduce new vrealloc() call and its subsidiary reach analog Roman Penyaev
2019-01-09 16:50 ` Matthew Wilcox
2019-01-10 10:08 ` Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 04/15] epoll: move private helpers from a header to the source Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 05/15] epoll: introduce user header structure and user index for polling from userspace Roman Penyaev
2019-01-09 16:40 ` Roman Penyaev [this message]
2019-01-09 16:40 ` [RFC PATCH 07/15] epoll: extend epitem struct with new members " Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 08/15] epoll: some sanity flags checks for epoll syscalls for polled epfd " Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 09/15] epoll: introduce stand-alone helpers for polling " Roman Penyaev
2019-01-09 17:29 ` Linus Torvalds
2019-01-10 10:03 ` Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 10/15] epoll: support polling from userspace for ep_insert() Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 11/15] epoll: offload polling to a work in case of epfd polled from userspace Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 12/15] epoll: support polling from userspace for ep_remove() Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 13/15] epoll: support polling from userspace for ep_modify() Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 14/15] epoll: support polling from userspace for ep_poll() Roman Penyaev
2019-01-09 16:40 ` [RFC PATCH 15/15] epoll: support mapping for epfd when polled from userspace 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=20190109164025.24554-7-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).