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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?/ifm+3bjDYpj7DFh6cTjQOpA/uvlogzxMwrwFX+GTdIfn+nLRiT55v7jVdY4?= =?us-ascii?Q?Rguvof9DqvjadOfJt5t0QFQrvgelPXaMAzTFBljNQkmBjO1DN6mYPo3CUT0L?= =?us-ascii?Q?aH1mI5K0nwm/KlcpQhXcwGITbGsKCIFisXzdHNlJBhZ7p5mA4HIoBunQUKc0?= =?us-ascii?Q?QH2gCrICtrdLjWUZUy13qZQnP/cDBIAN0UWeT/NJwMiJJKva8Kd7d+svXGdS?= =?us-ascii?Q?/FqJqRt8o2j1E9M9ByzzVReNydCfAb+C4sJbSOVI7Df5EzEtOHeVac9FzgBB?= =?us-ascii?Q?xFC2ePWYPaKk1XsUDsavfrFb45lsyat9cqxYgMiwdTX+ePgj8roC4pwODT/C?= =?us-ascii?Q?zJGJvfxMrinwvKwqNxn3GW8FNdPanHzsaKXlf/pKVyOHw54H29SHr5f6uCOQ?= =?us-ascii?Q?PUkyiEk9N/2WULS4uAwxyp55OY+nlF5mbiqzKf/S/rO1UhgKabrCtv5NFJ1e?= =?us-ascii?Q?18j3soxXSE8aB0Y1OVXpxHAcnKduecBTvufNAAy2cI1O+kuMs+TM8AXsncgT?= =?us-ascii?Q?TjS2J9wbqc6wTlp3F0GRRX8r8i9KXTsp15/2UayJgIZ5ZoWsZ95LAYGjEizP?= =?us-ascii?Q?cdTz4zXGawV5cXpTI15au9Vtff5G2o/DVQohPrSflZ79JG+gm1sSytkEX10u?= =?us-ascii?Q?ToX6fx9S4fnpu1pwGtN7JqLsVfvOqUYgDUYvvIXOtu4vAjNdXC03SMxPfLpn?= =?us-ascii?Q?+5v7Wx6CqyLIXXu7tQ9YI3u8YGvnqaDkUtqDUrWg9JY6gQyc8GIwvIy7aMMg?= =?us-ascii?Q?9aPcMnCDAp+CuvoMpFlOIScw6fFfxZ3RFGvuVzYQMUkGjL14NoUHPb6d6Lcy?= =?us-ascii?Q?YBgDz4D1IoE1+AomaDHt9kULruo8YdDItHnvJQLpL7vJAEjunRUmURytR7Fm?= =?us-ascii?Q?OE507iRAPMpW1+KXXcfLuf5HJSJxdQvym1c00G38p+PIg7hFuXN0wF54CSd9?= =?us-ascii?Q?w4ONmSExd9GM4GhK2l0Ua36kHeZ5rWc4VQbfcUrTMjl/WmQiUADKoviEbeNQ?= =?us-ascii?Q?OhUntydQEwNIIfowWPSjjmQqZtzwwio3G2IMsBZhgKF3C/ZyxvG9cIqW3q6Q?= =?us-ascii?Q?ENbBlBW4zTC0xPLgmGQOz4K0JK6qfJDLxWDxRh4t9uCQTiZ+Wsm8Qw9YFeTM?= =?us-ascii?Q?O7lC01N2jBuGFIPVGomenGieCRJFOV4M9kX6fjIlPHP7c79IWvotH0z7ss+l?= =?us-ascii?Q?cEM+9+22U9ooO9tP9/L80qi+xEtRmNQZwb/eLIY1cWvYBWXVv2z4XNffdQ4g?= =?us-ascii?Q?utm1DiAXw6z74NGdCKEbj62Abp/qYtcrada2r3vPQL63DjjkRYqJHVhAiHeY?= =?us-ascii?Q?QpKXfNiMNm8/8H7jvj7sCTJXK2ZWZIcmSPESC9XtrahwVf1N4ehZyE3HjeSh?= =?us-ascii?Q?2GPrK/D1buqVRGCsLHabAolZRcSRlXBtvDzws59j/ecz0X8IuDDFc0/wZUmB?= =?us-ascii?Q?k5lNPdVjpfAF/r3WqdcHms2MyVuOvDKDkIGMh0czj/q2aH0qXnNaaUo5z0k5?= =?us-ascii?Q?a374JzJZSo5xBGzNv6opZkYmNmtjcw3nOHI8LILBem6qh4Lcl21Ks5juw1eO?= =?us-ascii?Q?qaH2KAmATOiquNzrFb9JYjpPVFJNlU9qwiBGJbgL?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 58fc07f1-18f3-4b0e-4212-08dd4c4bae88 X-MS-Exchange-CrossTenant-AuthSource: CY5PR12MB6405.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Feb 2025 16:30:09.3875 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: oaprsguZsJRsuRqNKWUNAv0XV9oRgzvyMJWaqdGF4ZhUqI4cQDYMqn8AoKzI/aBOaGv1WA9je3cvn93biCRb5A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7841 On Thu, Feb 13, 2025 at 06:27:55AM -1000, Tejun Heo wrote: > Hello, > > On Thu, Feb 13, 2025 at 09:18:41AM +0100, Andrea Righi wrote: > > > Implement SCX_OPS_ALLOW_QUEUED_WAKEUP which allows BPF schedulers to choose > > > to enable ttwu_queue optimization. > > > > I'm wondering whether it makes sense to introduce a new SCX_OPS flag for > > this, considering that we already have the TTWU_QUEUE sched feature, that > > determines this behavior. > > > > Is this in perspective of a future scenario, when we may potentially have > > multiple scx schedulers running at the same time and they may want to set a > > different queued wakeup behavior? > > It's more that it can be a breaking change for schedulers that expect > ops.select_cpu() to be called on wakeups. e.g. If we make this behavior the > default, scx_layered as of the last relesae would break in an unobvious but > serious way - it'd fail to occupy CPUs fully as it'd be skipping picking > idle CPU and pushing tasks there for a noticeable portion of wakeups on > multi-LLC machines. The same holds for most of the C schedulers. > > Down the line, once everyone is onboard, we can maybe make it the default > and drop the flag but, for now, this needs to be opt-in. > > Thanks. Makes sense, thanks for the clarification. With that: Acked-by: Andrea Righi -Andrea