iomap: avoid memset iomap when iter is done#1184
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vfsci-bot[bot] wants to merge 1 commit intovfs.base.cifrom
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iomap: avoid memset iomap when iter is done#1184vfsci-bot[bot] wants to merge 1 commit intovfs.base.cifrom
vfsci-bot[bot] wants to merge 1 commit intovfs.base.cifrom
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When iomap_iter() finishes its iteration (returns <= 0), it is no longer necessary to memset the entire iomap and srcmap structures. In high-IOPS scenarios (like 4k randread NVMe polling with io_uring), where the majority of I/Os complete in a single extent map, this wasted memory write bandwidth, as the caller will just discard the iterator. Use this command to test: taskset -c 30 ./t/io_uring -p1 -d512 -b4096 -s32 -c32 -F1 -B1 -R1 -X1 -n1 -P1 /mnt/testfile IOPS improve about 5% on ext4 and XFS. However, we MUST still call iomap_iter_reset_iomap() to release the folio_batch if IOMAP_F_FOLIO_BATCH is set, otherwise we leak page references. Therefore, split the cleanup logic: always release the folio_batch, but skip the memset() when ret <= 0. Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
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Series: https://patchwork.kernel.org/project/linux-fsdevel/list/?series=1081838
Submitter: Fengnan Chang
Version: 1
Patches: 1/1
Message-ID:
<20260416030642.26744-1-changfengnan@bytedance.com>Base: vfs.base.ci
Lore: https://lore.kernel.org/linux-fsdevel/20260416030642.26744-1-changfengnan@bytedance.com
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