From 40fdea0284bb20814399da0484a658a96c735d90 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 2 Nov 2021 10:19:44 +0100 Subject: xen/balloon: add late_initcall_sync() for initial ballooning done MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Reported-by: Marek Marczykowski-Górecki Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20211102091944.17487-1-jgross@suse.com Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb76a64a2168..89a9ffc1ea16 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. -- cgit v1.2.3