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<div class="moz-cite-prefix">On 3/29/22 23:16, Li Wang wrote:<br>
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cite="mid:CAEemH2eAaSyZiXE4G792U72iQvmOwQcVe+RoMMqjF7Bc0uajGQ@mail.gmail.com">
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<div class="gmail_default" style="font-size:small">Waiman Long
<<a href="mailto:longman@redhat.com"
moz-do-not-send="true" class="moz-txt-link-freetext">longman@redhat.com</a>>
wrote:<br>
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<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
The patch looks good in general. However, maybe we should do
something like:<br>
<br>
diff --git a/clock_gettime04.c b/clock_gettime04.c<br>
index a8d2c5b..1ba218b 100644<br>
--- a/clock_gettime04.c<br>
+++ b/clock_gettime04.c<br>
@@ -92,11 +92,18 @@ static struct time64_variants variants[]
= {<br>
<br>
static void setup(void)<br>
{<br>
+ delta = 5;<br>
if (tst_is_virt(VIRT_ANY)) {<br>
tst_res(TINFO, "Running in a virtual
machine, multiply <br>
the delta by 10.");<br>
delta *= 10;<br>
}<br>
<br>
+ clock_getres(CLOCK_REALTIME, &res);<br>
+ precise_delta = delta + res.tv_nsec / 1000000;<br>
+<br>
+ clock_getres(CLOCK_REALTIME_COARSE, &res);<br>
+ coarse_delta = delta + res.tv_nsec / 1000000;<br>
+<br>
find_clock_gettime_vdso(&ptr_vdso_gettime,
&ptr_vdso_gettime64);<br>
}<br>
<br>
to avoid a coarse_delta that is too large for vm.<br>
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<div class="gmail_default" style="font-size:small">Thierically
that's right, we only make the resolution as additional
value to tolerate.</div>
<div class="gmail_default" style="font-size:small"><br>
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<div class="gmail_default" style="font-size:small">But I'm
afraid this is the part we can not guarantee especially
for VM. </div>
<span class="gmail_default" style="font-size:small">As f</span>rom
Eirik<span class="gmail_default" style="font-size:small">'s</span>
test history<span class="gmail_default"
style="font-size:small">, the KVM guest ever failed with
"150ms" delay:</span></div>
<div><span class="gmail_default" style="font-size:small"> </span>clock_gettime04.c:163:
TFAIL: CLOCK_BOOTTIME(vDSO with old kernel spec): Difference
between successive<span class="gmail_default"> </span>readings
greater than 50 ms (2): 150</div>
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<div class="gmail_default" style="font-size:small">If we
decide to go with your suggestion, I think we'd better skip
this test on VM.</div>
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<p>I see. So we really need more tolerance for vm. I am OK with your
current patch then.</p>
<p>Acked-by: Waiman Long <a class="moz-txt-link-rfc2396E" href="mailto:longman@redhat.com"><longman@redhat.com></a></p>
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