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| author | imp <imp@FreeBSD.org> | 2016-04-14 21:47:58 +0000 |
|---|---|---|
| committer | imp <imp@FreeBSD.org> | 2016-04-14 21:47:58 +0000 |
| commit | 91b03b024c254d4a91a4ab05ed9ad1c086328a1f (patch) | |
| tree | 4ee2db04e3dd53c8d999ef61db02b0c1f842db8f /sys/conf | |
| parent | 3b29c6c182f3cfb472b388ab3131c2353e4674bc (diff) | |
| download | FreeBSD-src-91b03b024c254d4a91a4ab05ed9ad1c086328a1f.zip FreeBSD-src-91b03b024c254d4a91a4ab05ed9ad1c086328a1f.tar.gz | |
New CAM I/O scheduler for FreeBSD. The default I/O scheduler is the same
as before. The common scheduling bits have moved from inline code in
each of the CAM periph drivers into a library that implements the
default scheduling.
In addition, a number of rate-limiting and I/O preference options can
be enabled by adding CAM_IOSCHED_NETFLIX to your config file. A number
of extra stats are also maintained. CAM_IOSCHED_NETFLIX isn't on by
default because it uses a separate BIO_READ and BIO_WRITE queue, so
doesn't honor BIO_ORDERED between these two types of operations. We
already didn't honor it for BIO_DELETE, and we don't depend on
BIO_ORDERED between reads and writes anywhere in the system (it is
currently used with BIO_FLUSH in ZFS to make sure some writes are
complete before others start and as a poor-man's soft dependency in
one place in UFS where we won't be issuing READs until after the
operation completes). However, out of an abundance of caution, it
isn't enabled by default.
Plus, this also brings in NCQ TRIM support for those SSDs that support
it. A black list is also provided for known rogues that use NCQ trim
as an excuse to corrupt the drive. It was difficult to separate out
into a separate commit.
This code has run in production at Netflix for over a year now.
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D4609
Diffstat (limited to 'sys/conf')
| -rw-r--r-- | sys/conf/files | 1 | ||||
| -rw-r--r-- | sys/conf/options | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/sys/conf/files b/sys/conf/files index 46e9768..8831f5c 100644 --- a/sys/conf/files +++ b/sys/conf/files @@ -68,6 +68,7 @@ usbdevs_data.h optional usb \ clean "usbdevs_data.h" cam/cam.c optional scbus cam/cam_compat.c optional scbus +cam/cam_iosched.c optional scbus cam/cam_periph.c optional scbus cam/cam_queue.c optional scbus cam/cam_sim.c optional scbus diff --git a/sys/conf/options b/sys/conf/options index 2283705..11e778f 100644 --- a/sys/conf/options +++ b/sys/conf/options @@ -329,6 +329,7 @@ CAM_DEBUG_TARGET opt_cam.h CAM_DEBUG_LUN opt_cam.h CAM_DEBUG_FLAGS opt_cam.h CAM_BOOT_DELAY opt_cam.h +CAM_NETFLIX_IOSCHED opt_cam.h SCSI_DELAY opt_scsi.h SCSI_NO_SENSE_STRINGS opt_scsi.h SCSI_NO_OP_STRINGS opt_scsi.h |
