padata_do_parallel(9)

💅 padata_do_parallel(9) — like, the padata parallelization function, bestie

okay so this one lives in the Kernel API Manual and it's genuinely one of my fave little kernel helpers, no cap. it's called padata_do_parallel, and yeah — it's the padata parallelization function. that's the whole vibe. ✨

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🌸 SYNOPSIS 🌸

int padata_do_parallel (struct padata_shell *ps , struct padata_priv
*padata , int *cb_cpu );

like, look at her. three args, one int coming back. main character energy fr fr 🎀

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🦋 ARGUMENTS 🦋

• ps — the padatashell. that's it, that's the whole description 💀 she's a padatashell, bestie, we love a girl who knows what she is.
• padata — the object to be parallelized. this is the thing you're sending off to do its little parallel moment 🌈
• cb_cpu — a pointer to the CPU that the serialization callback function should run on. okay so this is the important one: if that CPU is not in the serial cpumask of pinst (i.e. cpumask.cbcpu), then this function selects a fallback CPU for you. and if it can't find one at all? she returns -EINVAL. so like, expect that possibility, okay? 🙈

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💖 DESCRIPTION 💖

the parallelization callback function will run with BHs off. that's the whole description. short, sweet, and you absolutely need to know it. 👑

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⭐ NOTE ⭐

every single object that gets parallelized by padata_do_parallel must be seen by padata_do_serial. like, that's not optional. don't leave her hanging, bestie. the pairing is the whole point 🫶

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🔥 RETURN 🔥

0 on success, or else a negative error code. that's it. slay. 💅

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🧚 SEE ALSO 🧚

• kernel file ./kernel/padata.c
• padata_do_serial(9)
• padata_do_multithreaded(9)
• padata_set_cpumask(9)
• padata_alloc(9)
• padata_free(9)
• padata_alloc_shell(9)
• padata_free_shell(9)

go read the whole friend group, they all ate 💜

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aaaand that's the page!! 💖 this was pulled from ./kernel, dated October 2026, and yeah — she's padata_do_parallel(9) through and through. mwah 🎀✨🌸🦋