Messages in this thread | | | Date | Tue, 10 Dec 2019 11:53:08 +0530 | From | Bharata B Rao <> | Subject | Re: [PATCH 00/16] The new slab memory controller |
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On Mon, Dec 09, 2019 at 06:04:22PM +0000, Roman Gushchin wrote: > On Mon, Dec 09, 2019 at 05:26:49PM +0530, Bharata B Rao wrote: > > On Mon, Dec 09, 2019 at 02:47:52PM +0530, Bharata B Rao wrote: > Hello, Bharata! > > Thank you very much for the report and the patch, it's a good catch, > and the code looks good to me. I'll include the fix into the next > version of the patchset (I can't keep it as a separate fix due to massive > renamings/rewrites).
Sure, but please note that I did post only the core change without the associated header includes etc, where I took some short cuts.
> > > > > But that still doesn't explain why we don't hit this problem on x86. > > On x86 (and arm64) we're using vmap-based stacks, so the underlying memory is > allocated directly by the page allocator, bypassing the slab allocator. > It depends on CONFIG_VMAP_STACK.
I turned off CONFIG_VMAP_STACK on x86, but still don't hit any problems.
$ grep VMAP .config CONFIG_HAVE_ARCH_HUGE_VMAP=y CONFIG_HAVE_ARCH_VMAP_STACK=y # CONFIG_VMAP_STACK is not set
May be something else prevents this particular crash on x86?
> > Btw, thank you for looking into the patchset and trying it on powerpc. > Would you mind to share some results?
Sure, I will get back with more results, but initial numbers when running a small alpine docker image look promising.
With slab patches # docker stats --no-stream CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS 24bc99d94d91 sleek 0.00% 1MiB / 25MiB 4.00% 1.81kB / 0B 0B / 0B 0
Without slab patches # docker stats --no-stream CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS 52382f8aaa13 sleek 0.00% 8.688MiB / 25MiB 34.75% 1.53kB / 0B 0B / 0B 0
So that's an improvement of MEM USAGE from 8.688MiB to 1MiB. Note that this docker container isn't doing anything useful and hence the numbers aren't representative of any workload.
Regards, Bharata.
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