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From: David Rientjes <rientjes@google.com>
To: Mina Almasry <almasrymina@google.com>
Cc: mike.kravetz@oracle.com, shuah@kernel.org, shakeelb@google.com,
	 gthelen@google.com, Andrew Morton <akpm@linux-foundation.org>,
	 linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	 linux-kselftest@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [PATCH v12 4/9] hugetlb: disable region_add file_region coalescing
Date: Sat, 15 Feb 2020 17:25:13 -0800 (PST)
Message-ID: <alpine.DEB.2.21.2002151724510.244463@chino.kir.corp.google.com> (raw)
In-Reply-To: <20200211213128.73302-4-almasrymina@google.com>

On Tue, 11 Feb 2020, Mina Almasry wrote:

> A follow up patch in this series adds hugetlb cgroup uncharge info 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@google.com>

Acked-by: David Rientjes <rientjes@google.com>


  parent reply index

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 21:31 [PATCH v12 1/9] hugetlb_cgroup: Add hugetlb_cgroup reservation counter Mina Almasry
2020-02-11 21:31 ` [PATCH v12 2/9] hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations Mina Almasry
2020-02-15  0:50   ` Mike Kravetz
2020-02-16  1:21     ` David Rientjes
2020-02-11 21:31 ` [PATCH v12 3/9] hugetlb_cgroup: add reservation accounting for private mappings Mina Almasry
2020-02-11 21:31 ` [PATCH v12 4/9] hugetlb: disable region_add file_region coalescing Mina Almasry
2020-02-15  1:27   ` Mike Kravetz
2020-02-16  1:25   ` David Rientjes [this message]
2020-02-11 21:31 ` [PATCH v12 5/9] hugetlb_cgroup: add accounting for shared mappings Mina Almasry
2020-02-16  1:29   ` David Rientjes
2020-02-18 18:07   ` Mike Kravetz
2020-02-11 21:31 ` [PATCH v12 6/9] hugetlb_cgroup: support noreserve mappings Mina Almasry
2020-02-18 20:57   ` Mike Kravetz
2020-02-11 21:31 ` [PATCH v12 7/9] hugetlb: support file_region coalescing again Mina Almasry
2020-02-16  1:29   ` David Rientjes
2020-02-19  3:28   ` Mike Kravetz
2020-02-19  7:54     ` Mina Almasry
2020-02-19 23:36     ` [PATCH] hugetlb: Remove check_coalesce_bug debug code Mina Almasry
2020-02-20  0:07       ` Mike Kravetz
2020-02-11 21:31 ` [PATCH v12 8/9] hugetlb_cgroup: Add hugetlb_cgroup reservation tests Mina Almasry
2020-02-12  8:50   ` Sandipan Das
2020-02-20  0:05     ` Mina Almasry
2020-02-21  0:52   ` Mike Kravetz
2020-02-11 21:31 ` [PATCH v12 9/9] hugetlb_cgroup: Add hugetlb_cgroup reservation docs Mina Almasry
2020-02-20  0:03   ` Mina Almasry
2020-02-20  0:18   ` Mike Kravetz
2020-02-11 23:19 ` [PATCH v12 1/9] hugetlb_cgroup: Add hugetlb_cgroup reservation counter Andrew Morton
2020-02-18 14:21   ` Qian Cai
2020-02-18 18:35     ` Mina Almasry
2020-02-18 18:41       ` Qian Cai
2020-02-18 19:14       ` Mike Kravetz
2020-02-18 19:25         ` Mina Almasry
2020-02-18 21:36           ` Mina Almasry
2020-02-18 21:41             ` Mike Kravetz
2020-02-18 22:27               ` Mina Almasry
2020-02-19 19:05   ` Mina Almasry
2020-02-19 21:06     ` Andrew Morton
2020-02-20 19:22       ` Mina Almasry
2020-02-21  0:28         ` Andrew Morton
2020-02-21  0:41           ` Mike Kravetz
2020-02-21  1:52             ` Mina Almasry
2020-02-21 20:19       ` Mina Almasry

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