From aa0102f777d0155fa098b1e79eb9f4e8d1769279 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Sat, 16 Oct 2021 09:29:50 +0000
Subject: [PATCH] wqworker: favor level-triggered epoll for fairness
Sigfd->event_step needs priority over WQWorkers (and everything
else). Do that by running once per event_loop iteration rather
than looping inside event_step. This lowers throughput since it
requires more syscalls, but that's the price of fairness.
---
lib/PublicInbox/WQWorker.pm | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/lib/PublicInbox/WQWorker.pm b/lib/PublicInbox/WQWorker.pm
index 48b901bb..950bd170 100644
--- a/lib/PublicInbox/WQWorker.pm
+++ b/lib/PublicInbox/WQWorker.pm
@@ -6,7 +6,7 @@ package PublicInbox::WQWorker;
use strict;
use v5.10.1;
use parent qw(PublicInbox::DS);
-use PublicInbox::Syscall qw(EPOLLIN EPOLLEXCLUSIVE EPOLLET);
+use PublicInbox::Syscall qw(EPOLLIN EPOLLEXCLUSIVE);
use Errno qw(EAGAIN ECONNRESET);
use IO::Handle (); # blocking
@@ -14,19 +14,19 @@ sub new {
my ($cls, $wq, $sock) = @_;
$sock->blocking(0);
my $self = bless { sock => $sock, wq => $wq }, $cls;
- $self->SUPER::new($sock, EPOLLEXCLUSIVE|EPOLLIN|EPOLLET);
+ $self->SUPER::new($sock, EPOLLEXCLUSIVE|EPOLLIN);
$self;
}
sub event_step {
my ($self) = @_;
- my $n;
- do {
- $n = $self->{wq}->recv_and_run($self->{sock});
- } while ($n);
- return if !defined($n) && $! == EAGAIN; # likely
- warn "wq worker error: $!\n" if !defined($n) && $! != ECONNRESET;
- $self->{wq}->wq_atexit_child if $self->{sock} == $self->{wq}->{-wq_s2};
+ my $n = $self->{wq}->recv_and_run($self->{sock}) and return;
+ unless (defined $n) {
+ return if $! == EAGAIN;
+ warn "recvmsg: $!" if $! != ECONNRESET;
+ }
+ $self->{sock} == $self->{wq}->{-wq_s2} and
+ $self->{wq}->wq_atexit_child;
$self->close; # PublicInbox::DS::close
}
--
2.51.0