From: Michel Lespinasse <walken@google.com>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: akpm@linux-foundation.org, peterz@infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 02/11] lib/interval-tree: add an equivalent tree with [a,b) intervals
Date: Fri, 4 Oct 2019 04:02:24 -0700 [thread overview]
Message-ID: <20191004110224.GA253758@google.com> (raw)
In-Reply-To: <20191003201858.11666-3-dave@stgolabs.net>
On Thu, Oct 03, 2019 at 01:18:49PM -0700, Davidlohr Bueso wrote:
> +/* \
> + * Iterate over intervals intersecting [start;end) \
> + * \
> + * Note that a node's interval intersects [start;end) iff: \
> + * Cond1: ITSTART(node) < end \
> + * and \
> + * Cond2: start < ITEND(node) \
> + */ \
> + \
> +static ITSTRUCT * \
> +ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE end) \
> +{ \
> + while (true) { \
> + /* \
> + * Loop invariant: start <= node->ITSUBTREE \
Should be start < node->ITSUBTREE
> + * (Cond2 is satisfied by one of the subtree nodes) \
> + */ \
> + if (node->ITRB.rb_left) { \
> + ITSTRUCT *left = rb_entry(node->ITRB.rb_left, \
> + ITSTRUCT, ITRB); \
> + if (start < left->ITSUBTREE) { \
> + /* \
> + * Some nodes in left subtree satisfy Cond2. \
> + * Iterate to find the leftmost such node N. \
> + * If it also satisfies Cond1, that's the \
> + * match we are looking for. Otherwise, there \
> + * is no matching interval as nodes to the \
> + * right of N can't satisfy Cond1 either. \
> + */ \
> + node = left; \
> + continue; \
> + } \
> + } \
> + if (ITSTART(node) < end) { /* Cond1 */ \
> + if (start < ITEND(node)) /* Cond2 */ \
> + return node; /* node is leftmost match */ \
> + if (node->ITRB.rb_right) { \
> + node = rb_entry(node->ITRB.rb_right, \
> + ITSTRUCT, ITRB); \
> + if (start <= node->ITSUBTREE) \
Should be start < node->ITSUBTREE
> + continue; \
> + } \
> + } \
> + return NULL; /* No match */ \
> + } \
> +} \
Other than that, the change looks good to me.
This is something I might use, regardless of the status of converting
other current users.
The name "interval_tree_gen.h" makes it ambiguous wether gen stands
for "generic" or "generator". This may sounds like a criticism,
but it's not - I think it really stands for both :)
Reviewed-by: Michel Lespinasse <walken@google.com>
--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
next prev parent reply other threads:[~2019-10-04 11:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 20:18 [PATCH -next 00/11] lib/interval-tree: move to half closed intervals Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 01/11] mm: introduce vma_interval_tree_foreach_stab() Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 02/11] lib/interval-tree: add an equivalent tree with [a,b) intervals Davidlohr Bueso
2019-10-04 11:02 ` Michel Lespinasse [this message]
2019-10-03 20:18 ` [PATCH 03/11] drm/amdgpu: convert amdgpu_vm_it to half closed intervals Davidlohr Bueso
2019-10-04 6:54 ` Koenig, Christian
2019-10-04 11:36 ` Michel Lespinasse
2019-10-04 12:39 ` Christian König
2019-10-03 20:18 ` [PATCH 04/11] drm: convert drm_mm_interval_tree " Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 05/11] IB/hfi1: convert __mmu_int_rb " Davidlohr Bueso
2019-10-04 11:50 ` Michel Lespinasse
2019-10-04 19:41 ` Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 06/11] IB,usnic: convert usnic_uiom_interval_tree " Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 07/11] vhost: convert vhost_umem_interval_tree " Davidlohr Bueso
2019-10-04 12:10 ` Michel Lespinasse
2019-10-04 19:44 ` Davidlohr Bueso
2019-10-10 5:49 ` Jason Wang
2019-10-03 20:18 ` [PATCH 08/11] mm: convert vma_interval_tree " Davidlohr Bueso
2019-10-03 20:41 ` Matthew Wilcox
2019-10-04 12:30 ` Michel Lespinasse
2019-10-03 20:18 ` [PATCH 09/11] lib/interval-tree: convert interval_tree " Davidlohr Bueso
2019-10-03 22:50 ` kbuild test robot
2019-10-04 6:57 ` Koenig, Christian
2019-10-04 7:20 ` Koenig, Christian
2019-10-08 16:59 ` Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 10/11] lib: drop interval_tree_generic.h Davidlohr Bueso
2019-10-03 20:18 ` [PATCH 11/11] x86/mm, pat: convert pat tree to generic interval tree Davidlohr Bueso
2019-10-07 15:33 ` Ingo Molnar
2019-10-21 23:24 ` Davidlohr Bueso
2019-10-03 20:32 ` [PATCH -next 00/11] lib/interval-tree: move to half closed intervals Matthew Wilcox
2019-10-03 21:10 ` Davidlohr Bueso
2019-10-04 12:43 ` Michel Lespinasse
2019-10-04 0:26 ` Jason Gunthorpe
2019-10-04 2:48 ` Davidlohr Bueso
2019-10-04 13:15 ` Michel Lespinasse
2019-10-04 16:03 ` Matthew Wilcox
2019-10-04 19:35 ` Davidlohr Bueso
2019-10-04 17:45 ` Jason Gunthorpe
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