On Tue, 14 Oct 2025 17:38:29 +0530 Kundan Kumar <[email protected]> wrote:
> Currently, pagecache writeback is performed by a single thread. Inodes > are added to a dirty list, and delayed writeback is triggered. The single > writeback thread then iterates through the dirty inode list, and executes > the writeback. > > This series parallelizes the writeback by allowing multiple writeback > contexts per backing device (bdi). These writeback contexts are executed > as separate, independent threads, improving overall parallelism. Inodes > are distributed to these threads and are flushed in parallel. > > ... > > IOPS and throughput > =================== > With the affinity to allocation group we see significant improvement in > XFS when we write to multiple files in different directories(AGs). > > Performance gains: > A) Workload 12 files each of 1G in 12 directories(AGs) - numjobs = 12 > - NVMe device BM1743 SSD > Base XFS : 243 MiB/s > Parallel Writeback XFS : 759 MiB/s (+212%) > > - NVMe device PM9A3 SSD > Base XFS : 368 MiB/s > Parallel Writeback XFS : 1634 MiB/s (+344%) > > B) Workload 6 files each of 20G in 6 directories(AGs) - numjobs = 6 > - NVMe device BM1743 SSD > Base XFS : 305 MiB/s > Parallel Writeback XFS : 706 MiB/s (+131%) > > - NVMe device PM9A3 SSD > Base XFS : 315 MiB/s > Parallel Writeback XFS : 990 MiB/s (+214%) > > Filesystem fragmentation > ======================== > We also see that there is no increase in filesystem fragmentation > Number of extents per file: > A) Workload 6 files each 1G in single directory(AG) - numjobs = 1 > Base XFS : 17 > Parallel Writeback XFS : 17 > > B) Workload 12 files each of 1G to 12 directories(AGs)- numjobs = 12 > Base XFS : 166593 > Parallel Writeback XFS : 161554 > > C) Workload 6 files each of 20G to 6 directories(AGs) - numjobs = 6 > Base XFS : 3173716 > Parallel Writeback XFS : 3364984 Nice results. Is testing planned for other filesystems? _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
