Details

Reviewers

kib
markj

Commits

rG6d6fb6026d5f: umtx: Add bitset conditional wakeup functionality.
rG7caa29115b4a: umtx: Add bitset conditional wakeup functionality.

Summary

Bitset is a Linux emulation layer extension. This 32-bit mask, in which at least
one bit must be set, is used to select which threads should be woken up.

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

dchagin created this revision.Jul 20 2021, 2:09 PM

Herald added a subscriber: imp. · View Herald TranscriptJul 20 2021, 2:09 PM

dchagin requested review of this revision.Jul 20 2021, 2:09 PM

Harbormaster completed remote builds in B40553: Diff 92489.Jul 20 2021, 2:09 PM

dchagin added reviewers: kib, markj.Jul 20 2021, 2:19 PM

dchagin changed the repository for this revision from rS FreeBSD src repository - subversion to rG FreeBSD src repository.

followup D31248

Harbormaster completed remote builds in B40574: Diff 92517.Jul 20 2021, 7:28 PM

markj added inline comments.Jul 21 2021, 1:12 PM

sys/kern/kern_umtx.c
573	Why is it hard-coded to SHARED_QUEUE?
sys/sys/umtxvar.h
122–125	There is a hole here on LP64, if you add the new field here the size of the structure will not grow.

dchagin added inline comments.Jul 21 2021, 1:43 PM

sys/kern/kern_umtx.c
573	EXCLUSIVE_QUEUE used only by rw_lock, many umtx functions hide queue, umtxq_insert/umtxq_remove pair for example
sys/sys/umtxvar.h
122–125	good, thanks, will fix it

done

Harbormaster completed remote builds in B40602: Diff 92579.Jul 21 2021, 3:37 PM

kib added inline comments.Jul 21 2021, 3:49 PM

sys/kern/kern_umtx.c
574	if (uf == NULL) return (0); Then decrease indent level by one.
575	I do not know the intent, but what if there is a hole in the queue WRT bitmask? I mean, e.g. if we have thee elements with the uq_bitset values 1, 2, 4, and bitset is 5. Then you miss the element 4.
sys/sys/umtxvar.h
124	If the field is 32bit mask, then might be uint32_t type is better? It is explicit.