From: Eric Wong <e@80x24.org>
To: yahns-public@yhbt.net
Subject: [PATCH] avoid EPOLL_CTL_DEL calls on rack.hijack
Date: Tue, 17 Mar 2015 09:03:30 +0000 [thread overview]
Message-ID: <1426583010-30250-1-git-send-email-e@80x24.org> (raw)
We will support "un-hijacking", so the repeated ep_insert/ep_remove
sequences in the kernel will get expensive and complicated for our
user-land code, too.
---
lib/yahns/http_client.rb | 10 +++++-----
lib/yahns/queue_epoll.rb | 11 -----------
lib/yahns/queue_kqueue.rb | 6 ------
3 files changed, 5 insertions(+), 22 deletions(-)
diff --git a/lib/yahns/http_client.rb b/lib/yahns/http_client.rb
index 235decd..46ea3ec 100644
--- a/lib/yahns/http_client.rb
+++ b/lib/yahns/http_client.rb
@@ -259,12 +259,12 @@ class Yahns::HttpClient < Kgio::Socket # :nodoc:
end
# allow releasing some memory if rack.hijack is used
+ # n.b. we no longer issue EPOLL_CTL_DEL because it becomes more expensive
+ # (and complicated) as our hijack support will allow "un-hijacking"
+ # the socket.
def hijack_cleanup
- # we must issue EPOLL_CTL_DEL before hijacking (if we issue it at all),
- # because the hijacker may close use before we get back to the epoll worker
- # loop. EPOLL_CTL_DEL saves about 200 bytes of unswappable kernel memory,
- # so it can matter if we have lots of hijacked sockets.
- self.class.queue.queue_del(self) # EPOLL_CTL_DEL
+ # prevent socket from holding process up
+ Thread.current[:yahns_fdmap].forget(self)
@input = nil # keep env["rack.input"] accessible, though
@hs = nil # no need for the HTTP parser anymore
end
diff --git a/lib/yahns/queue_epoll.rb b/lib/yahns/queue_epoll.rb
index 4a10ce0..da90a95 100644
--- a/lib/yahns/queue_epoll.rb
+++ b/lib/yahns/queue_epoll.rb
@@ -32,17 +32,6 @@ class Yahns::Queue < SleepyPenguin::Epoll::IO # :nodoc:
Thread.current[:yahns_fdmap] = @fdmap
end
- # use only before hijacking, once hijacked, io may be unusable to us
- # It is not safe to call this unless it is an unarmed EPOLLONESHOT
- # object.
- def queue_del(io)
- # order does not really matter here, however Epoll::CTL_DEL
- # will free up ~200 bytes of unswappable kernel memory,
- # so we call it first
- epoll_ctl(Epoll::CTL_DEL, io, 0)
- @fdmap.forget(io)
- end
-
# returns an array of infinitely running threads
def worker_thread(logger, max_events)
Thread.new do
diff --git a/lib/yahns/queue_kqueue.rb b/lib/yahns/queue_kqueue.rb
index ce75793..4e5c133 100644
--- a/lib/yahns/queue_kqueue.rb
+++ b/lib/yahns/queue_kqueue.rb
@@ -41,12 +41,6 @@ class Yahns::Queue < SleepyPenguin::Kqueue::IO # :nodoc:
Thread.current[:yahns_fdmap] = @fdmap
end
- def queue_del(io)
- # do not bother with kevent EV_DELETE, it may be tricky to get right,
- # we only did it in epoll since Eric knows the epoll internals well.
- @fdmap.forget(io)
- end
-
# returns an array of infinitely running threads
def worker_thread(logger, max_events)
Thread.new do
--
2.3.2.209.gd67f9d5
reply other threads:[~2015-03-17 9:03 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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