nsecs_to_jiffies(9)

💖 NAME 💖

okay bestie, welcome to nsecs_to_jiffies(9) from the Kernel API Manual — this is the function that converts nsecs in u64 to jiffies. no cap, she’s iconic. 💅✨

🌸 SYNOPSIS 🌸

unsigned long nsecs_to_jiffies (u64 n );

🎀 ARGUMENTS 🎀

• n — nsecs in u64, that’s the whole mood 🫶

🦋 DESCRIPTION 🦋

So here’s the tea: unlike {m,u}secs_to_jiffies, the type of input here is not unsigned int but u64. and this doesn’t return MAX_JIFFY_OFFSET, because this function is designed for scheduler, not for use in device drivers to calculate timeout value. periodt. 💀✨

⭐ NOTE ⭐

okay nerd moment, the note is literally this:

       NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) ULLONG_MAX ns =
       18446744073.709551615 secs = about 584 years

💅 RETURN 💅

boom: nsecs converted to jiffies value. slay. 🔥

🌈 SEE ALSO 🌈

Kernel file ./kernel/time/time.c is the spot, and here’s the full friend group:

• jiffies_to_msecs(9)
• jiffies_to_usecs(9)
• mktime64(9)
• set_normalized_timespec64(9)
• ns_to_timespec64(9)
• __msecs_to_jiffies(9)
• __usecs_to_jiffies(9)
• timespec64_to_jiffies(9)
• jiffies_to_timespec64(9)
• jiffies_to_clock_t(9)
• clock_t_to_jiffies(9)
• jiffies_64_to_clock_t(9)
• nsec_to_clock_t(9)
• jiffies64_to_nsecs(9)
• jiffies64_to_msecs(9)
• nsecs_to_jiffies64(9)
• timespec64_add_safe(9)
• get_timespec64(9)
• put_timespec64(9)
• get_old_timespec32(9)
• put_old_timespec32(9)
• get_itimerspec64(9)
• put_itimerspec64(9)
• get_old_itimerspec32(9)
• put_old_itimerspec32(9)

byeee from the ./kernel/time source, dated October 2026 — this was nsecs_to_jiffies(9), signing off with main character energy. 💖✨