Re: [PATCH v9 4/8] hugetlb: disable region_add file_region coalescing

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 12/17/19 3:16 PM, Mina Almasry wrote:
> A follow up patch in this series adds hugetlb cgroup uncharge info the

*nit*
A follow up patch in this series adds hugetlb cgroup uncharge info to the

> file_region entries in resv->regions. The cgroup uncharge info may
> differ for different regions, so they can no longer be coalesced at
> region_add time. So, disable region coalescing in region_add in this
> patch.
> 
> Behavior change:
> 
> Say a resv_map exists like this [0->1], [2->3], and [5->6].
> 
> Then a region_chg/add call comes in region_chg/add(f=0, t=5).
> 
> Old code would generate resv->regions: [0->5], [5->6].
> New code would generate resv->regions: [0->1], [1->2], [2->3], [3->5],
> [5->6].
> 
> Special care needs to be taken to handle the resv->adds_in_progress
> variable correctly. In the past, only 1 region would be added for every
> region_chg and region_add call. But now, each call may add multiple
> regions, so we can no longer increment adds_in_progress by 1 in region_chg,
> or decrement adds_in_progress by 1 after region_add or region_abort. Instead,
> region_chg calls add_reservation_in_range() to count the number of regions
> needed and allocates those, and that info is passed to region_add and
> region_abort to decrement adds_in_progress correctly.
> 
> We've also modified the assumption that region_add after region_chg
> never fails. region_chg now pre-allocates at least 1 region for
> region_add. If region_add needs more regions than region_chg has
> allocated for it, then it may fail.
> 
> Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>
> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Thanks for the updated comments.  Still,
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

-- 
Mike Kravetz



[Index of Archives]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]

  Powered by Linux