Re: [PATCH v6 md-6.18 11/11] md/md-llbitmap: introduce new lockless bitmap
From: Yu Kuai <hidden>
Date: 2025-08-27 03:45:02
Also in:
dm-devel, linux-raid, lkml
Hi, 在 2025/08/26 17:52, Paul Menzel 写道:
It’d be great if you could motivate, why a lockless bitmap is needed > compared to the current implemention.
Se the performance test, old bitmap have global spinlock and is bad with fast disk. [snip the typo part]
How can/should this patch be tested/benchmarked?
There is pending mdadm patch, rfc verion can be used. Will work on formal version after this set is applied.
quoted hunk ↗ jump to hunk
--- a/drivers/md/md-bitmap.h +++ b/drivers/md/md-bitmap.h@@ -9,10 +9,26 @@ #define BITMAP_MAGIC 0x6d746962 +/* + * version 3 is host-endian order, this is deprecated and not used for new + * array + */ +#define BITMAP_MAJOR_LO 3 +#define BITMAP_MAJOR_HOSTENDIAN 3 +/* version 4 is little-endian order, the default value */ +#define BITMAP_MAJOR_HI 4 +/* version 5 is only used for cluster */ +#define BITMAP_MAJOR_CLUSTERED 5 > Move this to the header in a separate patch?
I prefer not, old bitmap use this as well. Thanks, Kuai