On Wed, Jan 25, 2023 at 12:08:58PM +0000, Catalin Marinas wrote: > That's an option. If there's too much churn to add a flag, an > alternative is to use the bottom bit of 'end' to set the noleaktrace > flag. Using the least significant bit won't work; there are allocations for CMA regions that can be specified to occur within the first 4 GB of memory, and would have an alloc-ranges of [0 0xffff_ffff]. I also don't think there's anything in the memblock documentation that ensures that those bits are supposed to be clear all the time. > Yet another idea is to avoid the kmemleak callback on all the 'phys' > memblock allocations. We can add the callback to the higher level > memblock_alloc() which returns a VA but the lower level 'phys' variants > could simply avoid it. However, I think we still need the > MEMBLOCK_ALLOC_NOLEAKTRACE flag for the kasan shadow allocation. Well, > given that this flag is not widely used, we can add explicit > kmemleak_ignore() calls in those four places. > > I think the latter, if it works, would be the least intrusive. I agree; I think using kmemleak_ignore() would be best. I will split that into series: 1 series that fixes the kmemleak issue with CMA regions by reverting Calvin's patch and adding a call to kmemleak_ignore in the call-stack I referenced earlier, and then another series that cleans up the usage of the flag. --Isaac
