Jason, One more query on same line.
Assume that base and extent are start and size of allocation. Is there infrastructure in Jemalloc to lookup an address (base + n ), n < extent ? My understanding is that such infrastructure does not exist in jemalloc. My use case involves checking whether a given pointer is part of a valid allocation or not. On Wed, Mar 25, 2015 at 2:14 PM, SNL <snl20...@gmail.com> wrote: > This looks relevant but never was pushed upstream. > > https://www.mail-archive.com/jemalloc-discuss@canonware.com/msg00027.html > > > Any thoughts on this patch set keeping in mind jemalloc-dev current state > ? Any design/architectural inputs are also appreciated. This seems to have > worked well for Alessandro who shared the patchset, I dont see these > changes in their current code base though. > > On Wed, Mar 25, 2015 at 11:25 AM, SNL <snl20...@gmail.com> wrote: > >> Does your use case allow you to wrap the allocator and keep a side table >> which supports iteration, or can you trace allocation activity and >> post-process it? >> >> => This is what I have implemented currently but this does not scale for >> multithreaded programs due to locking issues. I was pondering over idea of >> not doing any book keeping myself and use jemalloc data structures ( and >> efficient low level locking ) for my purpose. >> >> Is this not possible even when all my metadata objects ( which hold user >> allocation base and extent ) are fixed sized and allocated from a separate >> arena ? I was under the impression that I should be able to mask and find >> out offsets within chunk->region->pages and find out objects. As my objects >> are all fixed size, they would be contiguous in memory. Is this valid >> understanding ? >> >> >> On Tue, Mar 24, 2015 at 11:16 PM, Jason Evans <jas...@canonware.com> >> wrote: >> >>> On Mar 24, 2015, at 6:53 AM, SNL <snl20...@gmail.com> wrote: >>> >>> If this is not possible ( I see an old post which says jemalloc does not >>> have this infra but that was back in 2012 ). Is it possible to iterate over >>> just an arena and dump all allocations in it ? Basically, I have memory >>> pool implemented on top of jemalloc which holds metadata about all other >>> allocations jemalloc does, if I can iterate over this arena and get hold of >>> metadata, I can get hold of each allocation as well. >>> >>> Any thoughts would be appreciated. >>> >>> On Tue, Mar 24, 2015 at 5:28 PM, SNL <snl20...@gmail.com> wrote: >>> >>>> >>>> My use case is to walk through all live allocations ( the ones which >>>> are not freed yet) of all sizes the program ever made and dump it as the >>>> end of the program or on demand. I have looked at stats but I want >>>> something with even more details. Basically, the function should be able to >>>> iterate through all arenas and print details on following lines: >>>> >>>> arena = 1 base = 0x7fd7beb88800 size = 15 bytes etc >>>> >>>> Is there any api in jemalloc which already does subset of this ? Any >>>> pointers will be helpful. >>>> >>> >>> jemalloc doesn't support iteration over live allocations, and it's >>> unlikely to ever directly support iteration, because the feature imposes >>> nontrivial additional complexity for limited benefit. The closest thing >>> under consideration is https://github.com/jemalloc/jemalloc/issues/203, >>> but I don't plan to work on that until at least next year. >>> >>> Does your use case allow you to wrap the allocator and keep a side table >>> which supports iteration, or can you trace allocation activity and >>> post-process it? >>> >>> Jason >>> >> >> >> >> -- >> >> Cheers, >> Sunny. >> > > > > -- > > Cheers, > Sunny. > -- Cheers, Sunny.
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