read_pages(9)

💖 NAME 💖

okay so bestie, welcome to the read_pages(9) page in the Kernel API Manual — this is the manual entry for read_pages, and it does exactly this: it starts IO for a contiguous range of allocated folios in the page cache. slay. ✨

🌸 SYNOPSIS 🌸

void read_pages (struct readahead_control *rac );

🎀 ARGUMENTS 🎀

• rac — Readahead control. that’s the whole vibe, bestie 🫶

🦋 DESCRIPTION 🦋

okay so when read_pages returns, it is guaranteed that all of the folios will have been processed or removed, so that readahead_count(rac) == 0.

but — and this is the important little plot twist — that does not imply that readahead_index(rac) will be updated to point to the end of the originally requested range. why? because, for example, the filesystem may expand the range upwards. iykyk 😭

✨ SEE ALSO ✨

go read these too, bestie:

• Kernel file ./mm/readahead.c
• Readahead Overview(9)
• page_cache_ra_unbounded(9)
• readahead_expand(9)

mwah 💋 — this page lives in ./mm, and it’s dated October 2026. go off, kernel bestie 👑🦋