Messages in this thread | | | Date | Sat, 6 Jan 2024 15:07:21 +0800 | Subject | Re: [PATCH v3 0/2] iommu/iova: Make the rcache depot properly flexible | From | "zhangzekun (A)" <> |
| |
在 2024/1/6 12:21, Ethan Zhao 写道: > > On 1/2/2024 3:24 PM, Ido Schimmel wrote: >> On Thu, Dec 28, 2023 at 02:23:20PM +0200, Ido Schimmel wrote: >>> On Tue, Sep 12, 2023 at 05:28:04PM +0100, Robin Murphy wrote: >>>> v2: >>>> https://lore.kernel.org/linux-iommu/cover.1692641204.git.robin.murphy@arm.com/ >>>> >>>> Hi all, >>>> >>>> I hope this is good to go now, just fixed the locking (and threw >>>> lockdep at it to confirm, which of course I should have done to begin >>>> with...) and picked up tags. >>> Hi, >>> >>> After pulling the v6.7 changes we started seeing the following memory >>> leaks [1] of 'struct iova_magazine'. I'm not sure how to reproduce it, >>> which is why I didn't perform bisection. However, looking at the >>> mentioned code paths, they seem to have been changed in v6.7 as part of >>> this patchset. I reverted both patches and didn't see any memory leaks >>> when running a full regression (~10 hours), but I will repeat it to be >>> sure. >> FYI, we didn't see the leaks since reverting these two patches whereas >> before we saw them almost everyday, so I'm quite sure they introduced >> the leaks. > > Seems some magazines were not freed when one CPU is dead (hot > unplugged) ? > > static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain > *iovad) > { > struct iova_cpu_rcache *cpu_rcache; > struct iova_rcache *rcache; > unsigned long flags; > int i; > > for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { > rcache = &iovad->rcaches[i]; > cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); > spin_lock_irqsave(&cpu_rcache->lock, flags); > iova_magazine_free_pfns(cpu_rcache->loaded, iovad); > > + iova_magazine_free(cpu_rcache->loaded); > > iova_magazine_free_pfns(cpu_rcache->prev, iovad); > > + iova_magazine_free(cpu_rcache->prev); > > spin_unlock_irqrestore(&cpu_rcache->lock, flags); > } > } It seems cpu_rcache->loaded and cpu_rcache->prev will be freed in free_iova_rcaches(), and it should not cause memory leak because iova_magazine_free() will be called for each possible cpu. free_cpu_cached_iovas() is used to free cached iovas in magazines.
Thanks, Zekun
| |