[Crash-utility] Re: [PATCH] crash: add pcpu_info support

Dear all, We are a team developing the virtualization solution for the Linux kernel called OpenVZ. Since many people are running kernels patched by OpenVZ, they can definitely benefit from using the crash utility. Unfortunately, it's not possible to run crash on top of OpenVZ kernel without some slight modification of it's code. The reason is the introduction of some additional data structure to the OpenVZ kernel code which virtualize runqueues among other things. So the way crash needs to read struct rq is a bit different from vanilla kernel. Attached patch adds the needed functionality in a backward-compatible way. Can you please add it to crash devel tree?

------------------------------------------------------------------------ --- crash-4.0-4.12/defs.h.kirshil 2008-01-15 18:52:34.000000000 +0300 +++ crash-4.0-4.12/defs.h 2008-01-15 18:52:42.000000000 +0300 @@ -1429,6 +1429,9 @@ struct offset_table { long kmem_cache_cpu_freelist; long kmem_cache_cpu_page; long kmem_cache_cpu_node; + long pcpu_info_vcpu; + long pcpu_info_idle; + long vcpu_struct_rq; }; struct size_table { /* stash of commonly-used sizes */ @@ -1532,6 +1535,8 @@ struct size_table { /* stash of long upid; long kmem_cache_cpu; long cfs_rq; + long pcpu_info; + long vcpu_struct; }; struct array_table { --- crash-4.0-4.12/kernel.c.kirshil 2008-01-15 18:52:38.000000000 +0300 +++ crash-4.0-4.12/kernel.c 2008-01-15 18:52:42.000000000 +0300 @@ -475,6 +475,14 @@ kernel_init() if (!(kt->flags & DWARF_UNWIND)) kt->flags |= NO_DWARF_UNWIND; + if(STRUCT_EXISTS("pcpu_info")) { + MEMBER_OFFSET_INIT(pcpu_info_vcpu, "pcpu_info", "vcpu"); + MEMBER_OFFSET_INIT(pcpu_info_idle, "pcpu_info", "idle"); + MEMBER_OFFSET_INIT(vcpu_struct_rq, "vcpu_struct", "rq"); + STRUCT_SIZE_INIT(pcpu_info, "pcpu_info"); + STRUCT_SIZE_INIT(vcpu_struct, "vcpu_struct"); + } + BUG_bytes_init(); } --- crash-4.0-4.12/task.c.kirshil 2008-01-15 18:52:39.000000000 +0300 +++ crash-4.0-4.12/task.c 2008-01-15 18:53:56.000000000 +0300 @@ -5696,6 +5696,14 @@ get_idle_threads(ulong *tasklist, int nr cnt++; else BZERO(tasklist, sizeof(ulong) * NR_CPUS); + } else if (symbol_exists("pcpu_info") ){ + runq=symbol_value("pcpu_info"); /* vzk */ + runqbuf=GETBUF(SIZE(pcpu_info)); + for (i = 0; i < nr_cpus; i++, runq += SIZE(pcpu_info)) { + readmem(runq,KVADDR,runqbuf,SIZE(pcpu_info),"pcpu info",FAULT_ON_ERROR); + tasklist[i] = ULONG(runqbuf + OFFSET(pcpu_info_idle)); + if (IS_KVADDR(tasklist[i])) cnt++; + } } if (runqbuf) @@ -5777,13 +5785,15 @@ int get_active_set(void) { int i, cnt, per_cpu; - ulong runq, runqaddr; + ulong runq, runqaddr, pcpu_info = 0; char *runqbuf; if (tt->flags & ACTIVE_SET) return TRUE; - if (symbol_exists("runqueues")) { + if (symbol_exists("pcpu_info") && VALID_MEMBER(pcpu_info_vcpu)) { + pcpu_info = symbol_value("pcpu_info"); + } else if (symbol_exists("runqueues")) { runq = symbol_value("runqueues"); per_cpu = FALSE; } else if (symbol_exists("per_cpu__runqueues")) { @@ -5796,7 +5806,23 @@ get_active_set(void) runqbuf = GETBUF(SIZE(runqueue)); cnt = 0; - if (VALID_MEMBER(runqueue_curr) && per_cpu) { + if (pcpu_info != 0) { + ulong vcpu_struct; + char *pcpu_info_buf, *vcpu_struct_buf; + + pcpu_info_buf = GETBUF(SIZE(pcpu_info)); + vcpu_struct_buf = GETBUF(SIZE(vcpu_struct)); + for (i = 0; i < kt->cpus; i++, pcpu_info += SIZE(pcpu_info)) { + readmem(pcpu_info,KVADDR,pcpu_info_buf,SIZE(pcpu_info), "pcpu_info",FAULT_ON_ERROR); + vcpu_struct= ULONG(pcpu_info_buf +OFFSET(pcpu_info_vcpu)); + readmem(vcpu_struct,KVADDR,vcpu_struct_buf,SIZE(vcpu_struct),"pcpu_info->vcpu",FAULT_ON_ERROR); + tt->active_set[i] = ULONG(vcpu_struct_buf+OFFSET(vcpu_struct_rq)+OFFSET(runqueue_curr)); + if (IS_KVADDR(tt->active_set[i])) + cnt++; + } + FREEBUF(pcpu_info_buf); + FREEBUF(vcpu_struct_buf); + } else if (VALID_MEMBER(runqueue_curr) && per_cpu) { for (i = 0; i < kt->cpus; i++) { if ((kt->flags & SMP) && (kt->flags & PER_CPU_OFF)) { runq = symbol_value("per_cpu__runqueues") +