* Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx> [231011 22:52]: > > > 在 2023/10/10 22:17, Liam R. Howlett 写道: > > Users complained about OOM errors during fork without triggering > > compaction. This can be fixed by modifying the flags used in > > mas_expected_entries() so that the compaction will be triggered in low > > memory situations. Since mas_expected_entries() is only used during > > fork, the extra argument does not need to be passed through. > > > > Additionally, the testing in the maple tree fork testing needed to be > > altered to use the correct locking type so that allocations would not > > trigger sleeping and thus failures in the testing. The additional > > locking change requires rwsem support additions to the tools/ directory > > through the use of pthreads pthread_rwlock_t. With this change > > test_maple_tree works in userspace, as a module, and in-kernel. > > > > Users may notice that the system gave up early on attempting to start > > new processes instead of attempting to reclaim memory. > You still haven't updated check_forking() and bench_forking(). > It will still produce the same error as [1]. This did not show up on my testing, I will pull the bots config as I must be missing something in there. Thanks. > > [1] https://lore.kernel.org/oe-lkp/202309242123.7ebe65b5-oliver.sang@xxxxxxxxx/ > > > > Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4 > > Fixes: 54a611b60590 ("Maple Tree: add new data structure") > > Cc: <stable@xxxxxxxxxxxxxxx> > > Cc: jason.sim@xxxxxxxxxxx > > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> > > --- > > lib/maple_tree.c | 2 +- > > lib/test_maple_tree.c | 13 ++++++++---- > > tools/include/linux/rwsem.h | 40 +++++++++++++++++++++++++++++++++++++ > > 3 files changed, 50 insertions(+), 5 deletions(-) > > create mode 100644 tools/include/linux/rwsem.h > > > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > > index 0e00a84e8e8f..bb24d84a4922 100644 > > --- a/lib/maple_tree.c > > +++ b/lib/maple_tree.c > > @@ -5627,7 +5627,7 @@ int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries) > > /* Internal nodes */ > > nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap); > > /* Add working room for split (2 nodes) + new parents */ > > - mas_node_count(mas, nr_nodes + 3); > > + mas_node_count_gfp(mas, nr_nodes + 3, GFP_KERNEL); > > /* Detect if allocations run out */ > > mas->mas_flags |= MA_STATE_PREALLOC; > > diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c > > index 06959165e2f9..204743bc161c 100644 > > --- a/lib/test_maple_tree.c > > +++ b/lib/test_maple_tree.c > > @@ -9,6 +9,7 @@ > > #include <linux/maple_tree.h> > > #include <linux/module.h> > > +#include <linux/rwsem.h> > > #define MTREE_ALLOC_MAX 0x2000000000000Ul > > #define CONFIG_MAPLE_SEARCH > > @@ -2616,6 +2617,10 @@ static noinline void __init check_dup_gaps(struct maple_tree *mt, > > void *tmp; > > MA_STATE(mas, mt, 0, 0); > > MA_STATE(newmas, &newmt, 0, 0); > > + struct rw_semaphore newmt_lock; > > + > > + init_rwsem(&newmt_lock); > > + mt_set_external_lock(&newmt, &newmt_lock); > > if (!zero_start) > > i = 1; > > @@ -2625,9 +2630,9 @@ static noinline void __init check_dup_gaps(struct maple_tree *mt, > > mtree_store_range(mt, i*10, (i+1)*10 - gap, > > xa_mk_value(i), GFP_KERNEL); > > - mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE); > > + mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN); > > mt_set_non_kernel(99999); > > - mas_lock(&newmas); > > + down_write(&newmt_lock); > > ret = mas_expected_entries(&newmas, nr_entries); > > mt_set_non_kernel(0); > > MT_BUG_ON(mt, ret != 0); > > @@ -2640,9 +2645,9 @@ static noinline void __init check_dup_gaps(struct maple_tree *mt, > > } > > rcu_read_unlock(); > > mas_destroy(&newmas); > > - mas_unlock(&newmas); > > - mtree_destroy(&newmt); > > + __mt_destroy(&newmt); > > + up_write(&newmt_lock); > > } > > /* Duplicate many sizes of trees. Mainly to test expected entry values */ > > diff --git a/tools/include/linux/rwsem.h b/tools/include/linux/rwsem.h > > new file mode 100644 > > index 000000000000..83971b3cbfce > > --- /dev/null > > +++ b/tools/include/linux/rwsem.h > > @@ -0,0 +1,40 @@ > > +/* SPDX-License-Identifier: GPL-2.0+ */ > > +#ifndef _TOOLS__RWSEM_H > > +#define _TOOLS__RWSEM_H > > + > > +#include <pthread.h> > > + > > +struct rw_semaphore { > > + pthread_rwlock_t lock; > > +}; > > + > > +static inline int init_rwsem(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_init(&sem->lock, NULL); > > +} > > + > > +static inline int exit_rwsem(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_destroy(&sem->lock); > > +} > > + > > +static inline int down_read(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_rdlock(&sem->lock); > > +} > > + > > +static inline int up_read(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_unlock(&sem->lock); > > +} > > + > > +static inline int down_write(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_wrlock(&sem->lock); > > +} > > + > > +static inline int up_write(struct rw_semaphore *sem) > > +{ > > + return pthread_rwlock_unlock(&sem->lock); > > +} > > +#endif /* _TOOLS_RWSEM_H */
