On 02/01/2016 12:45 PM, Christian Borntraeger wrote: > On 01/28/2016 04:49 PM, Janosch Frank wrote: >> KVM statistics for VMs (no. of exits, halts and other special >> instructions) are currently only available in a summarized manner for >> all VMs. They are exported to userland through files in the kvm >> debugfs directory and used for performance monitoring, as well as VM >> problem detection with helper tools like kvm_stat. If a VM has >> problems and therefore creates a large number of exits, one can not >> easily find out which one it is, as there is no VM specific data. >> >> This patch adds a kvm debugfs subdirectory for each VM, which is named >> after its pid and file descriptor. They contain the same kind of files >> that are already in the kvm debugfs directory, but the data that is >> exported through them is now VM specific. >> >> CC: Dan Carpenter <dan.carpenter@xxxxxxxxxx> [includes fixes by Dan Carpenter] >> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx> > > for s390: > Tested-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > > > some questions below > > [...] >> >> +/* Worst case buffer size needed for holding an integer. */ >> +#define ITOA_MAX_LEN 12 > > 4294967295 has 10, so this is to cover the \0 and a potential "-", correct? Correct For the dir name we have 2 * ITOA_MAX_LEN, as it is %d-%d an we only need one \0 which accounts for the additional hyphen. I'm open for suggestions about how to make this clearer. > > > [...] >> @@ -3436,7 +3602,8 @@ static int kvm_init_debug(void) >> if (kvm_debugfs_dir == NULL) >> goto out; >> >> - for (p = debugfs_entries; p->name; ++p) { >> + kvm_debugfs_num_entries = 0; >> + for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) { > > Looks like we cannot use ARRAY_SIZE(kvm_stats_debugfs_item), so unless somebody > has a better idea we have to stick with kvm_debugfs_num_entries being calculated. > > >> if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir, >> (void *)(long)p->offset, >> stat_fops[p->kind])) >> > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html