From: sashiko-bot@kernel.org
To: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Cc: linux-s390@vger.kernel.org, "Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>
Subject: Re: [PATCH 04/14] s390/sclp_ctl: Replace get_zeroed_page() with kzalloc()
Date: Mon, 09 Nov 2026 09:05:20 +0000 [thread overview]
Message-ID: <sashiko-outbox-204656@kernel.org> (raw)
In-Reply-To: <20261108-s390-sclp-ready-v1-4-3e7c90eb6676@kernel.org>
> sclp_ctl_ioctl_sccb() allocates the SCCB that carries a user supplied
> SCLP command.
>
> This buffer 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.
>
> Performance difference between kmalloc() and __get_free_pages() is not
> measurable as both allocators take an object/page from a per-CPU list for
> fast path allocations.
>
> For the slow path the performance is anyway determined by the amount of
> reclaim involved rather than by what allocator is used.
>
> Replace use of get_zeroed_page() with kzalloc() and free_page() with
> kfree().
>
> Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Sashiko has reviewed this patch and found no issues.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261108-s390-sclp-ready-v1-0-3e7c90eb6676@kernel.org?part=4
next prev parent reply other threads:[~2026-11-09 9:05 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-08 8:58 [PATCH 00/14] s390/sclp: replace page allocator calls with k[mz]alloc() Mike Rapoport (Microsoft)
2026-11-08 8:58 ` [PATCH 01/14] s390/sclp_vt220: Replace get_zeroed_page() with kzalloc() Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 02/14] s390/sclp_config: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 03/14] s390/sclp_pci: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 04/14] s390/sclp_ctl: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot [this message]
2026-11-08 8:58 ` [PATCH 05/14] s390/sclp_con: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 06/14] s390/sclp_tty: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 07/14] s390/sclp: Replace __get_free_page() with kmalloc() Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 08/14] s390/sclp_sdias: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 09/14] s390/sclp_sd: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 10/14] s390/sclp_cmd: Replace page allocator calls with kzalloc() Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 11/14] s390/sclp_cpi: Replace get_zeroed_page() " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 12/14] s390/sclp_ftp: " Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 13/14] s390/sclp_mem: Replace page allocator calls with k[mz]alloc() Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
2026-11-08 8:58 ` [PATCH 14/14] s390/sclp_ap: Replace get_zeroed_page() with kzalloc() Mike Rapoport (Microsoft)
2026-11-09 9:05 ` sashiko-bot
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