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      <base href="https://bugs.freedesktop.org/">
    </head>
    <body><span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span> changed
          <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [CI] igt@perf_pmu@semaphore-wait-[vcs0|vecs0|bcs0] - Failed assertion: (double)(val[1] - val[0]) <= (1.0 + (tolerance)) * (double)(slept) && (double)(val[1] - val[0]) >= (1.0 - (tolerance)) * (double)(slept)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=104013">bug 104013</a>
          <br>
             <table border="1" cellspacing="0" cellpadding="8">
          <tr>
            <th>What</th>
            <th>Removed</th>
            <th>Added</th>
          </tr>

         <tr>
           <td style="text-align:right;">Status</td>
           <td>NEW
           </td>
           <td>RESOLVED
           </td>
         </tr>

         <tr>
           <td style="text-align:right;">Resolution</td>
           <td>---
           </td>
           <td>FIXED
           </td>
         </tr></table>
      <p>
        <div>
            <b><a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [CI] igt@perf_pmu@semaphore-wait-[vcs0|vecs0|bcs0] - Failed assertion: (double)(val[1] - val[0]) <= (1.0 + (tolerance)) * (double)(slept) && (double)(val[1] - val[0]) >= (1.0 - (tolerance)) * (double)(slept)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=104013#c5">Comment # 5</a>
              on <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [CI] igt@perf_pmu@semaphore-wait-[vcs0|vecs0|bcs0] - Failed assertion: (double)(val[1] - val[0]) <= (1.0 + (tolerance)) * (double)(slept) && (double)(val[1] - val[0]) >= (1.0 - (tolerance)) * (double)(slept)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=104013">bug 104013</a>
              from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
        <pre>commit c7b20c950276a41badd994324e1983760e44842b
Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
Date:   Sat Dec 2 00:14:52 2017 +0000

    igt/perf_pmu: Tighten semaphore-wait measurement

    Record the before/after semaphore-wait values around the sleep to try to
    reduce the inaccuracy from scheduler delays. Previously, the samples
    were taken before submitting the batch and then after synchronising its
    completion. The measurement will then be the total that the semaphore
    was being sampled, but with the extra syscalls intervening may have
    drifted from the sleep duration. To further reduce the disparity, wait
    for the batch to start executing before taking our samples.

    References: <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [CI] igt@perf_pmu@semaphore-wait-[vcs0|vecs0|bcs0] - Failed assertion: (double)(val[1] - val[0]) <= (1.0 + (tolerance)) * (double)(slept) && (double)(val[1] - val[0]) >= (1.0 - (tolerance)) * (double)(slept)"
   href="show_bug.cgi?id=104013">https://bugs.freedesktop.org/show_bug.cgi?id=104013</a>
    Signed-off-by: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
    Cc: Tvrtko Ursulin <<a href="mailto:tvrtko.ursulin@intel.com">tvrtko.ursulin@intel.com</a>>
    Reviewed-by: Tvrtko Ursulin <<a href="mailto:tvrtko.ursulin@intel.com">tvrtko.ursulin@intel.com</a>>

Once again, hopefully the last tweak required.</pre>
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