From: "Li,Rongqing" <lirongqing@baidu.com>
To: Peter Zijlstra <peterz@infradead.org>,
Michel Lespinasse <michel@lespinasse.org>
Cc: "dbueso@suse.de" <dbueso@suse.de>,
"mingo@kernel.org" <mingo@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: 答复: [PATCH] rbtree: stop iteration early in rb_find_first
Date: Wed, 25 Aug 2021 16:08:06 +0000 [thread overview]
Message-ID: <e9fac96f205e4b8f94432143052f93af@baidu.com> (raw)
In-Reply-To: <YSZD6suya8fR/2uY@hirez.programming.kicks-ass.net>
>>
>>
>> 10
>> /
>> 5
>> \
>> 10
>>
>> The search would stop after visiting node 5, and miss the leaf which
>> is the expected node to be returned.
thanks for explanation.
> Just to clarify; the current code *does* work here. The proposed patch
> breaks it.
true, my patch is wrong.
but rb_find_first seems have other issue. when the key is equal, we should search right leaf, not left leaf
rb_find_first should like below
while (node) {
int c = cmp(key, node);
if (c < 0) {
node = node->rb_left;
} else {
if (!c)
match = node;
node = node->rb_right;
}
}
since the node is inserted to right when the key is equal, see rb_add()
-Li
next prev parent reply other threads:[~2021-08-25 16:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-25 9:59 [PATCH] rbtree: stop iteration early in rb_find_first Li RongQing
2021-08-25 11:39 ` Peter Zijlstra
2021-08-25 11:53 ` Michel Lespinasse
2021-08-25 11:58 ` Michel Lespinasse
2021-08-25 12:31 ` Peter Zijlstra
2021-08-25 13:21 ` Peter Zijlstra
2021-08-25 16:08 ` Li,Rongqing [this message]
[not found] ` <90ea3457ddc7485fbc8db5f7ca5b07ab@baidu.com>
2021-08-25 17:18 ` 答复: " Peter Zijlstra
2021-08-25 18:26 ` 答复: " Li,Rongqing
2021-08-25 19:20 ` Peter Zijlstra
2021-08-26 5:03 ` 答复: " Li,Rongqing
2021-08-25 12:29 ` Peter Zijlstra
2021-08-25 12:32 ` Peter Zijlstra
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