Messages in this thread | | | Date | Wed, 16 Sep 2015 10:52:05 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4] perf, x86: Fix multi-segment problem of perf_event_intel_uncore |
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On Thu, Sep 17, 2015 at 01:17:12AM +0900, Taku Izumi wrote:
> +struct pci2phy_map { > + struct list_head list; > + int segment; > + int pbus_to_physid[256]; > +};
> +struct pci2phy_map *__find_pci2phy_map(int segment) > +{ > + struct pci2phy_map *map, *alloc = NULL; > + > + lockdep_assert_held(&pci2phy_map_lock); > + > +lookup: > + list_for_each_entry(map, &pci2phy_map_head, list) { > + if (map->segment == segment) > + goto end; > + } > + > + if (!alloc) { > + raw_spin_unlock(&pci2phy_map_lock); > + alloc = kmalloc(sizeof(struct pci2phy_map), GFP_KERNEL);
Do we want kzalloc() ? we unconditionally initialize the list and segment thingies, but that array is not initialized here. Or is there a better/safer value to initialize that array with?
Looking at uncore_pcibus_to_physid(), -1 might be a good value to use.
> + raw_spin_lock(&pci2phy_map_lock); > + > + if (!alloc) > + return NULL; > + > + goto lookup; > + } > + > + map = alloc; > + alloc = NULL; > + map->segment = segment; > + list_add_tail(&map->list, &pci2phy_map_head); > + > +end: > + kfree(alloc); > + return map; > +}
Other than that I think the patch looks OK now.
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