f833623b17
blktrace: backport upstream bugfix patches Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
67 lines
1.8 KiB
Diff
67 lines
1.8 KiB
Diff
From 4ad65be104d69a100354897e0f04602b4a68461d Mon Sep 17 00:00:00 2001
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From: Gwendal Grignou <gwendal@chromium.org>
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Date: Fri, 18 Aug 2017 15:00:22 -0700
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Subject: [PATCH 03/15] btt: Fix overlapping IO stats.
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Keep scanning the tree for overlapping IO otherwise Q2G and process
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traces will be incorrect.
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Let assume we have 2 IOs:
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A A+a
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|---------------------------------------|
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B B+b
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|-----------------|
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In the red/black tree we have:
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o -> [A,A+a]
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/ \
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left right
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/ \
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[...]o o -> [B, B+b]
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In the current code, if we would not be able to find [B+b] in the tree:
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B is greater than A, so we won't go left
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B+b is smaller than A+a, so we are not going right either.
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When we have a [X, X+x] IO to look for:
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We need to check for right when either:
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X+x >= A+a (for merged IO)
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and
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X > A (for overlapping IO)
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TEST=Check with a trace with overlapping IO: Q2C and Q2G are expected.
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Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
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Signed-off-by: Jens Axboe <axboe@kernel.dk>
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---
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btt/dip_rb.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/btt/dip_rb.c b/btt/dip_rb.c
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index 2aa7ffc..6efef6c 100644
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--- a/btt/dip_rb.c
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+++ b/btt/dip_rb.c
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@@ -57,7 +57,7 @@ struct io *rb_find_sec(struct rb_root *root, __u64 sec)
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__iop = rb_entry(n, struct io, rb_node);
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if (sec < BIT_START(__iop))
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n = n->rb_left;
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- else if (sec >= BIT_END(__iop))
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+ else if (sec > BIT_START(__iop))
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n = n->rb_right;
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else
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return __iop;
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@@ -82,7 +82,7 @@ void rb_foreach(struct rb_node *n, struct io *iop,
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}
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if (iop_s < this_s)
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rb_foreach(n->rb_left, iop, fnc, head);
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- if (this_e < iop_e)
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+ if ((this_e < iop_e) || (this_s < iop_s))
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rb_foreach(n->rb_right, iop, fnc, head);
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}
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}
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--
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1.8.3.1
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