Re: [libvirt] [PATCH v4] qemu: Introduce state_lock_timeout toqemu.conf

On Tue, Aug 28, 2018 at 04:40:16PM +0800, Yi Wang wrote: >When doing some job holding state lock for a long time, >we may come across error: >"Timed out during operation: cannot acquire state change lock" >Well, sometimes it's not a problem and users wanner continue s/wanner/want to/

>diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug >index ddc4bbf..f7287ae 100644 >--- a/src/qemu/libvirtd_qemu.aug >+++ b/src/qemu/libvirtd_qemu.aug >@@ -93,6 +93,7 @@ module Libvirtd_qemu = > | limits_entry "max_core" > | bool_entry "dump_guest_core" > | str_entry "stdio_handler" >+ | int_entry "state_lock_timeout" > here you add the option at the end of the 'process_entry' group > let device_entry = bool_entry "mac_filter" > | bool_entry "relaxed_acs_check" >diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf >index cd57b3c..8920a1a 100644 >--- a/src/qemu/qemu.conf >+++ b/src/qemu/qemu.conf >@@ -667,6 +667,16 @@ > # > #max_queued = 0 > >+ >+# When two or more threads want to work with the same domain they use a >+# job lock to mutually exclude each other. However, waiting for the lock >+# is limited up to state_lock_timeout seconds. >+# NB, strong recommendation to set the timeout longer than 30 seconds. >+# >+# Default is 30 >+# >+#state_lock_timeout = 60 But here in qemu.conf, you add it between the rpc entries. It seems we did not follow the structure with 'stdio_handler', but adding it either right after 'dump_guest_core' or at the end of file would be better than squeezing it between rpc entries.

>@@ -863,6 +868,9 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, > if (virConfGetValueUInt(conf, "keepalive_count", &cfg->keepAliveCount) < 0) > goto cleanup; > >+ if (virConfGetValueInt(conf, "state_lock_timeout", &cfg->stateLockTimeout) < 0) >+ goto cleanup; >+ But the parsed value is passed directly here, so '60' in the config file would result in 60 ms.

> > retry: > if ((!async && job != QEMU_JOB_DESTROY) && >diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in >index f1e8806..dc5de96 100644 >--- a/src/qemu/test_libvirtd_qemu.aug.in >+++ b/src/qemu/test_libvirtd_qemu.aug.in >@@ -105,3 +105,4 @@ module Test_libvirtd_qemu = > { "pr_helper" = "/usr/bin/qemu-pr-helper" } > { "swtpm_user" = "tss" } > { "swtpm_group" = "tss" } >+{ "state_lock_timeout" = "60" } This needs to be ordered properly - install the 'augeas' tool to see where 'make check' fails.