View source for CONFIG PREEMPT RT Patch

== Platforms Tested and in Use with CONFIG_PREEMPT_RT ==

{| class="wikitable" 
|-
! Processor !! Model #'s !! Kernel version(s) !! Contact(s) !! Comment(s)
|-
| Opteron || IBM LS21, LS22, HS21XM, HS22x, 3455, 3550, 3650 ||  2.6.16-rt22, 2.6.20-rt8  || [[User:Tytso | Theodore Ts'o]], [[User:Dvhart | Darren Hart]] || Systems have SMI Remediation support and handle ECC errors via the ibmprtm daemon.
|-
| Xeon    || IBM 6850-P4U            || 2.6.20-rt8, 2.6.21-rc6-rt0|| [[User:Sperryd | Dave Sperry]] ||
|-
| Intel  Xeon 2.4GHz with HT || HP xw8000  ||  2.6.29.3-rt12           || [[User:rdoursenaud | Raphaël Doursenaud]] ||
|-
| AMD Opteron 175 || ASUS A8N-SLI Premium  ||  2.6.29.3-rt12           || [[User:rdoursenaud | Raphaël Doursenaud]] ||
|-
| P4      || Compaq Evo N610         ||  2.6.16-rt22              || [[User:Sperryd | Dave Sperry]] ||
|-
| P3      || Celeron 1300            ||  2.6.21.5-rt14            || [[User:PostFactum | Oleksandr Natalenko]] ||
|-
| Intel   || Pentium Dual-Core T2330 ||  2.6.29.1-rt4            || [[User:PostFactum | Oleksandr Natalenko]] ||
|-
| Prescott|| PentiumD 3 GHz          ||  2.6.22.6-rt9             || [[User:BlackRaven | Dmitry Pisklov]] ||
|-
| Intel   || Pentium 4 2.4 GHz       ||  2.6.23.9-rt12           || [[User:Jaswinderlinuxrt | Jaswinder Singh]] ||
|-
| Intel   || Pentium 4 2.8 GHz with HT  ||  2.6.23.9-rt12           || [[User:Jaswinderlinuxrt | Jaswinder Singh]] ||
|-
| Intel   || [http://www.fujitsu-siemens.com/products/prof_accessories_mainboards/mainboards/industrial/d2151s.html FSC D2151S ] Celeron D 2.93 Ghz      ||  2.6.20-rt8               || [[User:Remy | Remy Bohmer]] || Avg. latency < 10us, worst case latency: < 30us (see Note 1)
|-
| Intel   || [http://www.fujitsu-siemens.com/products/prof_accessories_mainboards/mainboards/industrial/d2151s.html FSC D2151S ] Core 2 Duo E6300        ||  2.6.20-rt8               || [[User:Remy | Remy Bohmer]] || Avg. latency < 10us, worst case latency: < 30us (see Note 1)
|-
| Intel   || [http://www.asus.com/products.aspx?l1=3&l2=11&l3=307&l4=0&model=1179&modelmenu=1 Asus P5B] Core 2 Duo E6600 2.4GHz ||  2.6.23-rc4-rt1           || [[User:Remy | Remy Bohmer]] || Avg. latency < 10us, worst case latency: < 30us (see Note 1)
|-
| Intel   || Core 2 Quad Q6600 || 2.6.24.7-rt27 || [[User:Pauls]] || Works ok, but frequency scaling has to be turned off for decent results. A task run at 1 kHz repetition rate with low load was found to be t-distributed with 4 degrees of freedom, with 1% value 0.9842 ms, 99% value 1.0103 ms (ideal realtime performance would get exactly 1 ms for both values), with the frequency governor set to "performance".
|-
| Intel Core 2 Quad Q6600 || Gigabyte EP35C-DS3R|| 2.6.33.5-rt23 || [[User:rdoursenaud | Raphaël Doursenaud]] ||
|-
| Intel || Core 2 Quad Q9000 <br>HP DV7-2185dx|| 2.6.31-5-rt #6-Ubuntu SMP PREEMPT RT x86_64 || [[User:Dr. Tyrell | M A Chojnowski]] || Seems to work perfectly, but often seeing high userspace lock contentions.
|-
| Intel   || [http://www-307.ibm.com/pc/support/site.wss/quickPath.do?quickPathEntry=266874g IBM Thinkpad T43] Pentium M CPU 2 GHz   ||  2.6.23-rt3           || [[User:PhilK | PhilK]] || Avg. latency < 14us, worst case latency: < 32us 
|-
| Intel   || Pentium 4 (M) 1.8 GHz       ||  2.6.29.1-rt7           || [[User:Matthias Kaehlcke | Matthias Kaehlcke]] ||
|-
| ARM9 (v4t)|| [http://www.atmel.com/dyn/products/tools_card.asp?family_id=605&family_name=AT91SAM+32%2Dbit+ARM%2Dbased+Microcontrollers&tool_id=3507 Atmel AT91RM9200-EK]  (See AT91-Notes) ||  2.6.23.12-rt14 || [[User:Remy | Remy Bohmer]] || worst case latency: < 300us (see Note 1)
|-
| ARM9 (v4t)|| [http://wiki.emqbit.com/free-ecb-at91 FREE_ECB_AT91]  (See AT91-Notes) ||  2.6.23.12-rt14 || Carlos Camargo || 
|-
| ARM9 (v4t)|| [http://www.cirrus.com/en/products/pro/detail/P1053.html Cirrus EP9301] ||  2.6.29.1-rt7 || [[User:Matthias Kaehlcke | Matthias Kaehlcke]]
|-
| ARM9 (v5tej)|| [http://www.atmel.com/dyn/products/tools_card.asp?family_id=605&family_name=AT91SAM+32%2Dbit+ARM%2Dbased+Microcontrollers&tool_id=3820 Atmel AT91SAM9261]  (See AT91-Notes) ||  2.6.24.7-rt27 || [[User:Remy | Remy Bohmer]] || worst case latency: < 150us (see Note 1)
|-
| ARM9 (v5tej)|| [http://linux.omap.com/ TI] [http://tree.celinuxforum.org/CelfPubWiki/OSK OMAP5912 OSK] ||  2.6.23-rt1 || [http://vger.kernel.org/vger-lists.html#linux-omap OMAP ML] || A small additional OMAP specific patch on top of -rt is needed. [http://marc.info/?l=linux-omap&m=119634477133936&w=2 See ML].
|-
| ARM9 (v5tej)|| [http://www.ti.com/corp/docs/landing/davinci/index.html TI] [http://wiki.davincidsp.com/ DM6446 DaVinci] ||  2.6.23-rt1 || [http://linux.omap.com/pipermail/davinci-linux-open-source/ DaVinci ML] || A small additional DaVinci specific patch on top of -rt is needed. [http://linux.omap.com/pipermail/davinci-linux-open-source/2007-October/004283.html See ML].
|-
| ARM9 (v5tej)|| [http://www.embeddedarm.com/products/board-detail.php?product=TS-7800 TS-7800] Marvell MV88F5182 ARM9 500MHz ||  2.6.29.3-rt13 || [[User:falstaff | Stefan Agner]] || worst case latency: < 250us, see [http://www.agner.ch/linuxrealtime agner.ch] (german)
|-
| SH4 || [http://japan.renesas.com/fmwk.jsp?cnt=r2d_tools_product_landing.jsp&fp=/products/tools/os/Linux/sh_linux/r2d/ Renesas R2D/R2D+] SH7751R CPU || 2.6.21-rt2 and later || [http://vger.kernel.org/vger-lists.html#linux-sh linux-sh ML]
|-
| XScale || IXP425 || 2.6.21.4-rt13 || [[User:Georgem | George McCollister]]
|-
| ARM7TDMI || ml675003 || 2.6.26.6-rt11 || [[User:Georgem | George McCollister]]
|}
''Note 1'': latency is defined as the time between the moment an interrupt occurs in hardware, and the moment the corresponding interrupt-thread gets running.

''AT91-Notes'': The following issues are known on this architecture:
* Priority Inheritance Mutexes in userspace (PTHREAD_PRIO_INHERIT) only works since 2.6.23-rt1 with Glibc 2.5 and higher. Tested and stable with applications that match the memory locking scheme described on [[HOWTO:_Build_an_RT-application]].
* Clocksource and clockevent implementations are available, and are in mainline since 2.6.24-rc4. (or see [http://maxim.org.za/at91_26.html AT91-patchset]) Tickless and HRT both work, but not using them due to very high CPU load compared to a ticking kernel on preempt-rt.
* GPIO Interrupt handling is not stable which causes missing GPIO interrupts, fixed by [http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2007-November/044088.html patch]. This patch is integrated in 2.6.23.11-rt14 and newer (Without this patch, the Ethernet adapter (DM9000) on AT91SAM9261-EK does not work in combination with PREEMPT-RT.)
''Note 2'': A wide range of systems and architectures (various x86, ARM, PPC, MIPS) with a CONFIG_PREEMPT_RT patched mainline kernel is continuously tested at the [http://osadl.org/QA OSADL QA Farm Realtime] under idle and load conditions. Both [http://www.osadl.org/QA-Farm-Continuous-real-time-monitorin.qa-farm-monitoring.0.html continuous latency monitoring data] and [http://www.osadl.org/Latency-plot-of-system-in-rack-1-slot-1.qa-latencyplot-r1s1.0.html cyclictest-generated latency plots] are available on-line and updated as soon as new data become available. Here latency is defined as the time between a timer interrupt occurs or, if scheduled by other reasons, a process is enqueued, and the moment the corresponding waiting user-space program is about to be switched to.