Add DWPD (Drive Writes Per Day) rate limiting to control L2ARC write
speeds and protect SSD endurance. Write rate is constrained by the
minimum of l2arc_write_max and DWPD-calculated budget. Devices
accumulate unused write budget over 24-hour periods with automatic reset
and carry-over. Writes occur in controlled bursts (max 50MB) with
adaptive intervals to achieve target rates. Applies after initial device
fill.
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#18093
Transform L2ARC from single global feed thread to per-device threads,
enabling parallel writes to multiple L2ARC devices. Each device runs
its own feed thread independently, improving multi-device throughput.
Previously, a single thread served all devices sequentially; now each
device writes concurrently. Threads are created during device addition
and torn down on removal.
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#18093
This commit introduces per-sublist persistent markers that eliminate
redundant tail scanning between L2ARC iterations, providing significant
CPU efficiency improvements. Markers are pre-allocated during device
initialization and properly cleaned up during device removal.
The implementation uses conditional behavior based on device capacity:
small devices (capacity < arc_c) retain original HEAD/TAIL scanning
based on ARC warmup state, while large devices (capacity >= arc_c)
use the persistent marker approach for optimal CPU efficiency.
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#18093
Similar to BRT, DDT ZAP can be destroyed by sync context when it
becomes empty. Respectively similar to BRT introduce RW-lock to
protect open context methods from the destruction.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#18115
For kernel builds on FreeBSD, we redefine `__printf__` to
`__freebsd_kprintf__`, to support FreeBSD kernel printf(9) extensions
with clang.
In OpenZFS various printf related functions are declared with
`__attribute__((format(printf, X, Y)))`, so these won't work with the
above redefinition. With clang 21 and higher, this leads to errors
similar to:
sys/contrib/openzfs/module/zfs/spa_misc.c:414:38: error: passing
'printf' format string where 'freebsd_kprintf' format string is
expected [-Werror,-Wformat]
414 | (void) vsnprintf(buf, sizeof (buf), fmt, adx);
| ^
Since attribute names can always be spelled with leading and trailing
double underscores, rename these instances.
Note that in the FreeBSD base system we usually use `__printflike` from
`<sys/cdefs.h>`, but that does not apply to OpenZFS.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Signed-off-by: Dimitry Andric <dimitry@andric.com>
Closes#18095
Unlike other ZAP consumers due to compression DDT does not know
how big entry it is reading from ZAP. Due to this it called
zap_length_uint64_by_dnode() and zap_lookup_uint64_by_dnode(),
each of which does full ZAP entry lookup.
Introduction of the combined ZAP method dramatically reduces the
CPU overhead and locks contention at DBUF layer.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#18048
As was previously done for BRT, avoid holding/releasing DDT ZAP
dnodes for every access. Instead hold the dnodes during all their
life time, never releasing.
While at this, add _by_dnode() interfaces for zap_length_uint64()
and zap_count(), actively used by DDT code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#18047
Postponing entry removal from the DDT log in case of hit till later
single-threaded sync stage allows to make ddl_tree stable during
multi-threaded ZIO processing stage. It allows to drop the DDT lock
before the search instead of after, reducing the contention a lot.
Actually ddt_log_update_entry() was already handling the case of
entry present in the active log, so we only need to remove it from
flushing log, if the entry happen to be there.
My tests with parallel 4KB block writes show throughput increase
from 480MB/s (122K blocks/s) to 827MB/s (212K blocks/s), even
though still limited by the global DDT lock contention.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#18044
Previous code effectively enforced that all async free ZIOs were
_issued_ within the TXG timeout. But they could take forever to
complete, especially if the required metadata were not in ARC.
This patch introduces periodic waits every 2000 ZIOs, which should
give at least somewhat reasonable TXG timings even for single HDD
pools with empty ARC. And makes them complete within half of the
TXG timeout, since we might still need time to sync DDT and BRT.
While there, change zfs_max_async_dedup_frees semantics to include
also clone and gang blocks, which are similar. Bump the default
value from set long ago to be more forgiving to block cloning
(still not having logs and benefiting from large TXGs), now that
we have better working time limits. The limit now is a possible
amount of dirty data produced by BRT updates.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#18043
ddt_lookup() in zio_ddt_write() might require synchronous DDT ZAP
read. Running it from interrupt taskq might lead to deadlock.
Inclusion of ZIO_STAGE_DDT_WRITE into ZIO_BLOCKING_STAGES should
hopefully fix that, even though I am not sure how I got there.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#17981
Use 64-bit POSIX off_t in user space instead of the Linux kernel type
loff_t. This is enforced at configure time via AC_SYS_LARGEFILE and
AC_CHECK_SIZEOF([off_t]). loff_t remains in shared headers where they
mirror Linux VFS interfaces, and on FreeBSD we typedef loff_t to off_t
in those headers since libc does not provide it.
Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Moch <mail@alexmoch.com>
Closes#18020
Before this change DDT lock was taken 4 times per written block,
and as effectively a pool-wide lock it can be highly congested.
This change introduces a new per-entry dde_io_lock, protecting some
fields during I/O ready and done stages, so that we don't need the
global lock there.
According to my write tests on 64-thread system with 4KB blocks this
significantly reduce the global lock contention, reducing CPU usage
from 100% to expected ~80%, and increasing write throughput by 10%.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes#17960
This is mostly a placeholder; it's not actually clear if a boot
environment makes any sense for userspace. Still, "posix" is the likely
future name of libzpool as a port, and this define is mandatory, so lets
roll with it for now.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#17861
Pull all of the internal debug infrastructure up in to the zfs
code to clean up the layering. Remove all the dodgy usage of
SET_ERROR and DTRACE_PROBE from the spl. Luckily it was
lightly used in the spl layer so we're not losing much.
Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#17861
Ameer Hamza