On Dec 30, 2021 / 21:08, Douglas Gilbert wrote: > A long time ago this driver's store was allocated by kmalloc() or > alloc_pages(). When this was switched to vmalloc() the author > noticed slower ramdisk access times and more variability in repeated > tests. So try going back with sgl_alloc_order() to get uniformly > sized allocations in a sometimes large scatter gather _array_. That > array is the basis of maintaining O(1) access to the store. > > Using sgl_alloc_order() and friends requires CONFIG_SGL_ALLOC > so add a 'select' to the Kconfig file. > > Remove kcalloc() in resp_verify() as sgl_s can now be compared > directly without forming an intermediate buffer. This is a > performance win for the SCSI VERIFY command implementation. > > Make the SCSI COMPARE AND WRITE command yield the offset of the > first miscompared byte when the compare fails (as required by > T10). > > This patch previously depended on: "[PATCH v4 0/4] scatterlist: > add new capabilities". However while that patchset is being > considered, those functions have been replicated by the previous > patch with a "sdeb_" prefix so they can be used by this patch. > > Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> Doug, thank you for your work on scsi_debug. This patch touches the reset write pointer handler for scsi_debug ZBC devices. I have confirmed that the handler works as expected after applying this patch. Good. Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> -- Best Regards, Shin'ichiro Kawasaki
