[libvirt] [PATCH 7/7] virsh: Add setiothreads command

John Ferlan jferlan at redhat.com
Thu Mar 19 17:08:28 UTC 2015


https://bugzilla.redhat.com/show_bug.cgi?id=1161617

Add command to allow adding and removing IOThreads from the domain including
the configuration and live domain.

$ virsh setiothreads --help
  NAME
    setiothreads - change number of IOThreads

  SYNOPSIS
    setiothreads <domain> <count> [--config] [--live] [--current]

  DESCRIPTION
    Change the number of IOThreads in the guest domain.

  OPTIONS
    [--domain] <string>  domain name, id or uuid
    [--count] <number>  number of IOThreads
    --config         affect next boot
    --live           affect running domain
    --current        affect current domain

Assuming a domain with multiple IOThreads assigned to various threads and
trying to remove an IOThread assigned to a disk resource results in an
error on removal attempt:

$ virsh iothreadsinfo $dom
 IOThread ID     CPU Affinity
 ---------------------------------------------------
  1               2
  2               3
  3               0-3

$ virsh setiothreads $dom 1
error: invalid argument: cannot remove IOThread 2 since it is being used by disk path '/home/vm-images/iothr-vol1'

Adding an IOThread to a domain and then removing it:

$ virsh iothreadsinfo $dom
No IOThreads found for the domain

$ virsh setiothreads $dom 1
$ virsh iothreadsinfo $dom
 IOThread ID     CPU Affinity
 ---------------------------------------------------
  1               0-3

$ virsh setiothreads $dom 0
$ virsh iothreadsinfo $dom
No IOThreads found for the domain
$

Invalid number of IOThreads provided:

$ virsh setiothreads $dom -1
error: Invalid number of IOThreads

$

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 tools/virsh-domain.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/virsh.pod      | 17 +++++++++++
 2 files changed, 99 insertions(+)

diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 1d8225c..69d2a94 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -6978,6 +6978,82 @@ cmdIOThreadPin(vshControl *ctl, const vshCmd *cmd)
 }
 
 /*
+ * "setiothreads" command
+ */
+static const vshCmdInfo info_setiothreads[] = {
+    {.name = "help",
+     .data = N_("change number of IOThreads")
+    },
+    {.name = "desc",
+     .data = N_("Change the number of IOThreads in the guest domain.")
+    },
+    {.name = NULL}
+};
+
+static const vshCmdOptDef opts_setiothreads[] = {
+    {.name = "domain",
+     .type = VSH_OT_DATA,
+     .flags = VSH_OFLAG_REQ,
+     .help = N_("domain name, id or uuid")
+    },
+    {.name = "count",
+     .type = VSH_OT_INT,
+     .flags = VSH_OFLAG_REQ,
+     .help = N_("number of IOThreads")
+    },
+    {.name = "config",
+     .type = VSH_OT_BOOL,
+     .help = N_("affect next boot")
+    },
+    {.name = "live",
+     .type = VSH_OT_BOOL,
+     .help = N_("affect running domain")
+    },
+    {.name = "current",
+     .type = VSH_OT_BOOL,
+     .help = N_("affect current domain")
+    },
+    {.name = NULL}
+};
+
+static bool
+cmdSetIOThreads(vshControl *ctl, const vshCmd *cmd)
+{
+    virDomainPtr dom;
+    int count = 0;
+    bool ret = false;
+    bool config = vshCommandOptBool(cmd, "config");
+    bool live = vshCommandOptBool(cmd, "live");
+    bool current = vshCommandOptBool(cmd, "current");
+    unsigned int flags = VIR_DOMAIN_AFFECT_CURRENT;
+
+    VSH_EXCLUSIVE_OPTIONS_VAR(current, live);
+    VSH_EXCLUSIVE_OPTIONS_VAR(current, config);
+
+    if (config)
+        flags |= VIR_DOMAIN_AFFECT_CONFIG;
+    if (live)
+        flags |= VIR_DOMAIN_AFFECT_LIVE;
+
+    if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
+        return false;
+
+    if (vshCommandOptInt(cmd, "count", &count) < 0 || count < 0) {
+        vshError(ctl, "%s", _("Invalid number of IOThreads"));
+        goto cleanup;
+    }
+
+    if (virDomainSetIOThreads(dom, count, flags) < 0)
+        goto cleanup;
+
+    ret = true;
+
+ cleanup:
+    virDomainFree(dom);
+    return ret;
+}
+
+/*
  * "cpu-compare" command
  */
 static const vshCmdInfo info_cpu_compare[] = {
@@ -12903,6 +12979,12 @@ const vshCmdDef domManagementCmds[] = {
      .info = info_iothreadpin,
      .flags = 0
     },
+    {.name = "setiothreads",
+     .handler = cmdSetIOThreads,
+     .opts = opts_setiothreads,
+     .info = info_setiothreads,
+     .flags = 0
+    },
     {.name = "send-key",
      .handler = cmdSendKey,
      .opts = opts_send_key,
diff --git a/tools/virsh.pod b/tools/virsh.pod
index 8262a45..3376e49 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -1416,6 +1416,23 @@ If no flag is specified, behavior is different depending on hypervisor.
 B<Note>: The expression is sequentially evaluated, so "0-15,^8" is
 identical to "9-14,0-7,15" but not identical to "^8,0-15".
 
+=item B<setiothreads> I<domain> I<count>
+[[I<--config>] [I<--live>] | [I<--current>]]
+
+Change the number of IOThreads in a guest domain. The I<count> value may be
+limited by host or hypervisor. A value of zero removes all IOThreads from
+the guest domain. If an IOThread is currently assigned to a disk resource
+such as via the B<attach-disk> command, then an attempt to remove the
+IOThread will fail.
+
+If I<--live> is specified, affect a running guest. If the guest is not
+running an error is returned.
+If I<--config> is specified, affect the next boot of a persistent guest.
+If I<--current> is specified or I<--live> and I<--config> are not specified,
+affect the current guest state.
+Both I<--live> and I<--config> flags may be given, but if not flag is
+specified, behavior is dfferent depending on hypervisor.
+
 =item B<managedsave> I<domain> [I<--bypass-cache>]
 [{I<--running> | I<--paused>}] [I<--verbose>]
 
-- 
2.1.0




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