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Avila" Subject: Re: [PATCH RFC v4 2/3] sched: Avoid placing RT threads on cores handling long softirqs Message-ID: References: <20221003232033.3404802-1-jstultz@google.com> <20221003232033.3404802-3-jstultz@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-TM-AS-GCONF: 00 X-Proofpoint-GUID: KxCxNSzAfLsdmfurS5LGG_jdHkiHK9xV X-Proofpoint-ORIG-GUID: ODVnp4hg9pQZmEQzWk9AMOVApp4C_Gzi X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_04,2022-10-20_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 adultscore=0 priorityscore=1501 bulkscore=0 spamscore=0 mlxlogscore=724 lowpriorityscore=0 clxscore=1015 suspectscore=0 mlxscore=0 malwarescore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210200074 X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 19, 2022 at 03:09:15PM -0700, John Stultz wrote: Hi John, [...] > So I'll go ahead and simplify the check to just the LONG_SOFTIRQ_MASK > & (active | pending softirqs) check. This should avoid the need to > pull the cpu_rq(cpu)->curr value and simplify things. In my reading of your approach if you find a way to additionally indicate long softirqs being handled by the remote ksoftirqd, it would cover all obvious/not-corner cases. > -john