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authorJuergen Gross <jgross@suse.com>2021-11-02 10:19:44 +0100
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>2021-11-04 12:59:17 -0500
commit40fdea0284bb20814399da0484a658a96c735d90 (patch)
treebc4df00b32521fde95c18ceec8b47e9967249a2c /Documentation
parenteae446b7654f25b2ca42ed0de54d7005e126fdac (diff)
downloadlinux-40fdea0284bb20814399da0484a658a96c735d90.tar.gz
xen/balloon: add late_initcall_sync() for initial ballooning done
When running as PVH or HVM guest with actual memory < max memory the hypervisor is using "populate on demand" in order to allow the guest to balloon down from its maximum memory size. For this to work correctly the guest must not touch more memory pages than its target memory size as otherwise the PoD cache will be exhausted and the guest is crashed as a result of that. In extreme cases ballooning down might not be finished today before the init process is started, which can consume lots of memory. In order to avoid random boot crashes in such cases, add a late init call to wait for ballooning down having finished for PVH/HVM guests. Warn on console if initial ballooning fails, panic() after stalling for more than 3 minutes per default. Add a module parameter for changing this timeout. [boris: replaced pr_info() with pr_notice()] Cc: <stable@vger.kernel.org> Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20211102091944.17487-1-jgross@suse.com Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index fb76a64a216894..89a9ffc1ea1681 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6357,6 +6357,13 @@
improve timer resolution at the expense of processing
more timer interrupts.
+ xen.balloon_boot_timeout= [XEN]
+ The time (in seconds) to wait before giving up to boot
+ in case initial ballooning fails to free enough memory.
+ Applies only when running as HVM or PVH guest and
+ started with less memory configured than allowed at
+ max. Default is 180.
+
xen.event_eoi_delay= [XEN]
How long to delay EOI handling in case of event
storms (jiffies). Default is 10.