Re: [libvirt] [PATCH] Don't fail lxc domain start when memory controller support is missing

On Fri, Oct 15, 2010 at 10:15:02AM +0200, Guido Günther wrote: > Hi, > starting of lxc domains currently fails if memory controller support is > disabled in the kernel. Attached patch fixes this by ignoring the error > in case the files don't exist in the cgroup filesystem. I didn't add the > same exceptions for the recent hard and soft limit code since if somebody > sets this values he probably wants them enforced. O.k. to apply? In fact I missed one hunk. Here's a better patch with some commnents. -- Guido

>From b0f6c1628a3654c8a49382cd5b29577fddfe3f1c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Guido=20G=C3=BCnther?= <agx(a)sigxcpu.org&gt; Date: Fri, 15 Oct 2010 10:01:38 +0200 Subject: [PATCH] Don't fail lxc domain start when memory controller support is missing Debian stock kernel has CONFIG_CGROUP_MEM_RES_CTLR disabled due to the overhead [1]. Allow to start containers if the corresponding files in the cgroup filesystem are missing. This fixes Debian bug #566180 [2]. [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=534964 [2] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=566180 --- src/lxc/lxc_controller.c | 4 +++- src/lxc/lxc_driver.c | 11 ++++++++--- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index 20616b8..2a4f113 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -107,7 +107,9 @@ static int lxcSetContainerResources(virDomainDefPtr def) virReportSystemError(-rc, _("Unable to set memory limit for domain %s"), def->name); - goto cleanup; + /* Don't fail if we can't set memory due to lack of kernel support */ + if (rc != -ENOENT) + goto cleanup; } if(def->mem.hard_limit) { diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index df814da..8085169 100644 --- a/src/lxc/lxc_driver.c +++ b/src/lxc/lxc_driver.c @@ -485,7 +485,7 @@ static int lxcDomainGetInfo(virDomainPtr dom, lxc_driver_t *driver = dom->conn->privateData; virDomainObjPtr vm; virCgroupPtr cgroup = NULL; - int ret = -1; + int ret = -1, rc; lxcDriverLock(driver); vm = virDomainFindByUUID(&driver->domains, dom->uuid); @@ -515,10 +515,15 @@ static int lxcDomainGetInfo(virDomainPtr dom, "%s", _("Cannot read cputime for domain")); goto cleanup; } - if (virCgroupGetMemoryUsage(cgroup, &(info->memory)) < 0) { + if ((rc = virCgroupGetMemoryUsage(cgroup, &(info->memory))) < 0) { lxcError(VIR_ERR_OPERATION_FAILED, "%s", _("Cannot read memory usage for domain")); - goto cleanup; + if (rc == -ENOENT) { + /* Don't fail if we can't read memory usage due to a lack of + * kernel support */ + info->memory = 0; + } else + goto cleanup; } }