Linux Low-Latency Tracing for Multicore Hard Real-Time Systems

<div>Histograms generated by<span class="monospace"> npt</span> for <svg height="11.773pt" id="M25" style="vertical-align:-0.2454996pt" version="1.1" viewbox="-0.0498162 -11.5275 17.5728 11.773" width="17.5728pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z" id="g121-47"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="480" vert-adv-y="480"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,6.24,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z" id="g121-46"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="480" vert-adv-y="480"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,12.48,-5.741)"><path d="M253 635C142 635 71 555 71 471C71 400 113 353 178 316C143 295 107 268 91 252C70 231 46 202 46 157C46 50 132 -12 241 -12C329 -12 442 52 442 168C442 257 379 305 311 343C354 374 380 398 388 407C407 428 417 458 417 487C417 568 348 635 253 635ZM240 600C288 600 340 564 340 481C340 422 314 387 279 360C207 395 148 426 148 499C148 549 181 600 240 600ZM252 23C188 23 129 72 129 163C129 218 162 266 211 298C288 261 360 217 360 144C360 68 312 23 252 23Z" id="g58-54"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g></svg> loops on a<span class="monospace"> PREEMPT_RT</span> patched kernel with writer and timer<span class="monospace"> LTTng-UST</span> tracing.</div>

Advances in Computer Engineering

Linux Low-Latency Tracing for Multicore Hard Real-Time Systems

Figure 7