From b47de2471c0ed4f6edabf26b435d40559e71692b Mon Sep 17 00:00:00 2001
From: "Eric Wong (Contractor, The Linux Foundation)" <e@80x24.org>
Date: Wed, 18 Apr 2018 09:13:08 +0000
Subject: [PATCH] v2writable: reduce partititions by one
git fast-import and the main V2Writable process combined takes
about one CPU, so avoid having too many Xapian partitions which
cause unnecessary I/O contention.
---
lib/PublicInbox/V2Writable.pm | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 1cc4b005..66f8a8a3 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -22,8 +22,11 @@ use IO::Handle;
my $PACKING_FACTOR = 0.4;
# assume 2 cores if GNU nproc(1) is not available
-sub nproc () {
- int($ENV{NPROC} || `nproc 2>/dev/null` || 2);
+sub nproc_parts () {
+ my $n = int($ENV{NPROC} || `nproc 2>/dev/null` || 2);
+ # subtract for the main process and git-fast-import
+ $n -= 1;
+ $n < 1 ? 1 : $n;
}
sub count_partitions ($) {
@@ -73,7 +76,7 @@ sub new {
rotate_bytes => int((1024 * 1024 * 1024) / $PACKING_FACTOR),
last_commit => [], # git repo -> commit
};
- $self->{partitions} = count_partitions($self) || nproc();
+ $self->{partitions} = count_partitions($self) || nproc_parts();
bless $self, $class;
}
--
2.50.0