From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>,
Anthony PERARD <anthony.perard@citrix.com>,
Ian Jackson <ian.jackson@eu.citrix.com>, Wei Liu <wl@xen.org>
Subject: [Xen-devel] [PATCH] tools/libxl: make default of max event channels dependant on vcpus
Date: Thu, 26 Mar 2020 10:45:57 +0100 [thread overview]
Message-ID: <20200326094557.13822-1-jgross@suse.com> (raw)
Today the maximum number of event channels for a guest is defaulting
to 1023. For large guests with lots of vcpus this is not enough, as
e.g. the Linux kernel uses 7 event channels per vcpu, limiting the
guest to about 140 vcpus.
Instead of requiring to specify the allowed number of event channels
via the "event_channels" domain config option, make the default
depend on the maximum number of vcpus of the guest.
In order not to regress current configs use 1023 as the minimum
default setting.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
tools/libxl/libxl_create.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index e7cb2dbc2b..eddd0e98e5 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -226,7 +226,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
b_info->iomem[i].gfn = b_info->iomem[i].start;
if (!b_info->event_channels)
- b_info->event_channels = 1023;
+ b_info->event_channels = min(1023, b_info->max_vcpus * 8 + 255);
libxl__arch_domain_build_info_setdefault(gc, b_info);
libxl_defbool_setdefault(&b_info->dm_restrict, false);
--
2.16.4
next reply other threads:[~2020-03-26 9:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-26 9:45 Juergen Gross [this message]
2020-03-26 9:54 ` [Xen-devel] [PATCH] tools/libxl: make default of max event channels dependant on vcpus Jan Beulich
2020-03-26 10:00 ` Jürgen Groß
2020-03-26 10:05 ` Jan Beulich
2020-03-26 10:11 ` Jürgen Groß
2020-03-26 10:29 ` Jürgen Groß
2020-03-26 12:36 ` Andrew Cooper
2020-03-26 12:42 ` Jürgen Groß
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=20200326094557.13822-1-jgross@suse.com \
--to=jgross@suse.com \
--cc=anthony.perard@citrix.com \
--cc=ian.jackson@eu.citrix.com \
--cc=wl@xen.org \
--cc=xen-devel@lists.xenproject.org \
/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).