Messages in this thread | | | Date | Thu, 16 Mar 2023 17:04:18 +0800 | From | Leo Yan <> | Subject | Re: [PATCH v5 11/16] perf kvm: Use histograms list to replace cached list |
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On Thu, Mar 16, 2023 at 12:42:53AM -0700, Namhyung Kim wrote:
[...]
> > static struct kvm_event *find_create_kvm_event(struct perf_kvm_stat *kvm, > > struct event_key *key, > > struct perf_sample *sample) > > { > > struct kvm_event *event; > > - struct list_head *head; > > + struct hist_entry *he; > > + struct kvm_info *ki; > > > > BUG_ON(key->key == INVALID_KEY); > > > > - head = &kvm->kvm_events_cache[kvm_events_hash_fn(key->key)]; > > - list_for_each_entry(event, head, hash_entry) { > > - if (event->key.key == key->key && event->key.info == key->info) > > - return event; > > + ki = zalloc(sizeof(*ki)); > > + if (!ki) { > > + pr_err("Failed to allocate kvm info\n"); > > + return NULL; > > } > > > > - event = kvm_alloc_init_event(kvm, key, sample); > > - if (!event) > > + kvm->events_ops->decode_key(kvm, key, ki->name); > > + he = hists__add_entry_ops(&kvm_hists.hists, &kvm_ev_entry_ops, > > + &kvm->al, NULL, NULL, NULL, ki, sample, true); > > The hists__add_entry{,_ops} can return either a new entry > or an existing one. I think it'd leak the 'ki' when it returns > the existing one. You may deep-copy it in hist_entry__init() > and always free the 'ki' here.
Thanks for pointing out this, Namhyung. I will fix it.
@Arnaldo, do you want me to send an appending patch, or will you drop this patch series from your branch so I send a new patch set?
> Another thought on this. Lots of fields in the hist_entry are > not used for kvm. We might split the hist_entry somehow > so that we can use unnecessary parts only. But that could > be a future project. :)
Yeah, I found now hist_entry contains many fields (branch_info/mem_info/kvm_info/block_info); we can consider to refactor the struct hist_entry to use an abstract pointer to refer tool's specific data, this could be easily extend hist_entry to support more tools.
Thanks, Leo
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