Re: [PATCH 2/4] ice: use kzalloc() to allocate staging buffer for reading from GNSS
From: Mike Rapoport <rppt@kernel.org>
Date: 2026-07-02 14:41:04
Also in:
intel-wired-lan, lkml
On Thu, Jul 02, 2026 at 03:49:36PM +0200, Przemek Kitszel wrote:
On 7/1/26 15:57, Mike Rapoport (Microsoft) wrote:quoted
ice_gnss_read() uses get_zeroed_page() to allocate a staging buffer for reading GNSS module data via I2C bus. 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 (local) Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> --- drivers/net/ethernet/intel/ice/ice_gnss.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c index 8fd954f1ebd6..7d21c3417b0b 100644 --- a/drivers/net/ethernet/intel/ice/ice_gnss.c +++ b/drivers/net/ethernet/intel/ice/ice_gnss.c@@ -2,6 +2,7 @@ /* Copyright (C) 2021-2022, Intel Corporation. */ #include "ice.h" +#include <linux/slab.h> #include "ice_lib.h" /**@@ -124,7 +125,7 @@ static void ice_gnss_read(struct kthread_work *work) data_len = min_t(typeof(data_len), data_len, PAGE_SIZE); - buf = (char *)get_zeroed_page(GFP_KERNEL); + buf = kzalloc(PAGE_SIZE, GFP_KERNEL);nit: from the code it is clear that we read at most a page, and @data_len stores the actual amount needed comment: I don't know why we limit to a page, it's outside of the scope of this series, but likely you have removed the limit (which will go into the loop - single AQ call is likely limited by a PAGE too).
Not sure I follow how the limit changed. buf remains PAGE_SIZE regardless of allocation API.
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Thanks! -- Sincerely yours, Mike.