Messages in this thread | | | Subject | Re: [PATCH v2] mm/mremap: Don't account pages in vma_to_resize() | From | Dmitry Safonov <> | Date | Wed, 21 Jul 2021 21:18:30 +0100 |
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On 7/21/21 9:08 PM, Dmitry Safonov wrote: > On 7/21/21 9:05 PM, Andrew Morton wrote: >> On Wed, 21 Jul 2021 14:21:54 +0100 Dmitry Safonov <0x7f454c46@gmail.com> wrote: >> >>>> Let's not do this. >>>> Account memory in mremap() fast-path for growing VMAs or in move_vma() >>>> for actually moving things. The same simpler way as it's done by >>>> vm_stat_account(), but with a difference to call >>>> security_vm_enough_memory_mm() before copying/adjusting VMA. >>>> >>>> Originally noticed by Chen Wandun: >>>> https://lkml.kernel.org/r/20210717101942.120607-1-chenwandun@huawei.com >>> >>> The patch by Chen Wandun still makes sense with this v2. >>> Heh :-) >> >> Should >> https://lkml.kernel.org/r/20210717101942.120607-1-chenwandun@huawei.com >> still be applied then? Did you ack it? >> > > Yes, please keep that patch with > Acked-by: Dmitry Safonov <dima@arista.com> > > This one comes on the top to correct accounting for MREMAP_DONTUNMAP.
Please, also wait for reviews for this one. I think it's correct and simplifies the complex code, but now I look into the code again, I see that: : /* : * MREMAP_DONTUNMAP is always a move and it does not allow resizing : * in the process. : */ : if (flags & MREMAP_DONTUNMAP && : (!(flags & MREMAP_MAYMOVE) || old_len != new_len)) : return ret;
So, this part can be dropped: > Fixes: e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
But I think the patch still makes sense.
Brian, can I have your review on it?
Thanks, Dmitry
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