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| author | Feng Tang <feng.tang@intel.com> | 2023-09-20 15:44:13 +0800 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2023-10-02 11:54:32 +0200 |
| commit | e519ce7a26b4c877d834e4234e8d24478448c0d3 (patch) | |
| tree | 552610af91b780033e9e0094f2edc5d37efaf1e8 /mm/slub.c | |
| parent | 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa (diff) | |
| download | linux-e519ce7a26b4c877d834e4234e8d24478448c0d3.tar.gz linux-e519ce7a26b4c877d834e4234e8d24478448c0d3.tar.bz2 linux-e519ce7a26b4c877d834e4234e8d24478448c0d3.zip | |
mm/slub: add sanity check for slub_min/max_order cmdline setup
Currently there are 2 parameters could be setup from kernel cmdline:
slub_min_order and slub_max_order. It's possible that the user
configured slub_min_order is bigger than the default slub_max_order
[1], which can still take effect, as calculate_oder() will use MAX_ORDER
as a fallback to check against, but has some downsides:
* the kernel message about SLUB will be strange in showing min/max
orders:
SLUB: HWalign=64, Order=9-3, MinObjects=0, CPUs=16, Nodes=1
* in calculate_order() called by each slab, the 2 loops of
calc_slab_order() will all be meaningless due to slub_min_order
is bigger than slub_max_order
* prevent future code cleanup like in [2].
Fix it by adding some sanity check to enforce the min/max semantics.
[1]. https://lore.kernel.org/lkml/21a0ba8b-bf05-0799-7c78-2a35f8c8d52a@os.amperecomputing.com/
[2]. https://lore.kernel.org/lkml/20230908145302.30320-7-vbabka@suse.cz/
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c index f7940048138c..b36e5eb0ccb7 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4711,6 +4711,9 @@ static int __init setup_slub_min_order(char *str) { get_option(&str, (int *)&slub_min_order); + if (slub_min_order > slub_max_order) + slub_max_order = slub_min_order; + return 1; } @@ -4721,6 +4724,9 @@ static int __init setup_slub_max_order(char *str) get_option(&str, (int *)&slub_max_order); slub_max_order = min_t(unsigned int, slub_max_order, MAX_ORDER); + if (slub_min_order > slub_max_order) + slub_min_order = slub_max_order; + return 1; } |