Re: [PATCH 3/4] scsi: ipr: use kmalloc() to allocate IPR dump buffer memory

On 6/30/26 12:54 PM, Mike Rapoport (Microsoft) wrote:
> IPR dump machinery allocates memory to save adapter's crash dump using
> __get_free_page().
> 
> This memory can be allocated with kmalloc() as there's nothing special
> about it to go directly to the page allocator.
> 
> kmalloc() provides a better API that does not require ugly casts and
> kfree() does not need to know the size of the freed object.
> 
> Replace use of __get_free_page() with kmalloc().
> 
> Link: https://lore.kernel.org/all/[email protected]
> Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
> ---
>   drivers/scsi/ipr.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
> index d207e5e81afe..5a212bfdeec2 100644
> --- a/drivers/scsi/ipr.c
> +++ b/drivers/scsi/ipr.c
> @@ -2893,7 +2893,7 @@ static int ipr_sdt_copy(struct ipr_ioa_cfg *ioa_cfg,
>   	       (ioa_dump->hdr.len + bytes_copied) < max_dump_size) {
>   		if (ioa_dump->page_offset >= PAGE_SIZE ||
>   		    ioa_dump->page_offset == 0) {
> -			page = (__be32 *)__get_free_page(GFP_ATOMIC);
> +			page = kmalloc(PAGE_SIZE, GFP_ATOMIC);
>   
>   			if (!page) {
>   				ipr_trace;
> @@ -3226,7 +3226,7 @@ static void ipr_release_dump(struct kref *kref)
>   	spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
>   
>   	for (i = 0; i < dump->ioa_dump.next_page_index; i++)
> -		free_page((unsigned long) dump->ioa_dump.ioa_data[i]);
> +		kfree(dump->ioa_dump.ioa_data[i]);
>   
>   	vfree(dump->ioa_dump.ioa_data);
>   	kfree(dump);
> 
I _think_ we can replace this with kvmalloc, and allocate the entire
dump buffer in one go. Once switched to kmalloc() it's kinda pointless
to allocate separate page-sized buffers here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
[email protected]                               +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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