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Reduce stack usage by dsl_dataset_destroy() 

Move dsl_dataset_t local variable from the stack to the heap.
This reduces the stack usage of this function from 2048 bytes
to 176 bytes for x84_64 arches.
This commit is contained in:
Brian Behlendorf 2010-06-29 10:11:32 -07:00
parent 428870ff73
commit 7334572416
3 changed files with 22 additions and 9 deletions
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From: Brian Behlendorf <behlendorf1@llnl.gov>
Subject: [PATCH] fix stack dsl_dataset_destroy
Move dsl_dataset_t local variable from the stack to the heap.
This reduces the stack usage of this function from 2048 bytes
to 176 bytes for x84_64 arches.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

22
module/zfs/dsl_dataset.c
View File

@ -1033,7 +1033,7 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
dsl_dir_t *dd; dsl_dir_t *dd;
uint64_t obj; uint64_t obj;
struct dsl_ds_destroyarg dsda = { 0 }; struct dsl_ds_destroyarg dsda = { 0 };
dsl_dataset_t dummy_ds = { 0 }; dsl_dataset_t *dummy_ds;
dsda.ds = ds; dsda.ds = ds;
@ -1053,8 +1053,9 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
} }
dd = ds->ds_dir; dd = ds->ds_dir;
dummy_ds.ds_dir = dd; dummy_ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
dummy_ds.ds_object = ds->ds_object; dummy_ds->ds_dir = dd;
dummy_ds->ds_object = ds->ds_object;
/* /*
* Check for errors and mark this ds as inconsistent, in * Check for errors and mark this ds as inconsistent, in
@ -1063,11 +1064,11 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
dsl_dataset_destroy_begin_sync, ds, NULL, 0); dsl_dataset_destroy_begin_sync, ds, NULL, 0);
if (err) if (err)
goto out; goto out_free;
err = dmu_objset_from_ds(ds, &os); err = dmu_objset_from_ds(ds, &os);
if (err) if (err)
goto out; goto out_free;
/* /*
* remove the objects in open context, so that we won't * remove the objects in open context, so that we won't
@ -1104,14 +1105,14 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
} }
if (err != ESRCH) if (err != ESRCH)
goto out; goto out_free;
rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
rw_exit(&dd->dd_pool->dp_config_rwlock); rw_exit(&dd->dd_pool->dp_config_rwlock);
if (err) if (err)
goto out; goto out_free;
/* /*
* Blow away the dsl_dir + head dataset. * Blow away the dsl_dir + head dataset.
@ -1127,7 +1128,7 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
err = dsl_dataset_origin_rm_prep(&dsda, tag); err = dsl_dataset_origin_rm_prep(&dsda, tag);
if (err) { if (err) {
dsl_dir_close(dd, FTAG); dsl_dir_close(dd, FTAG);
goto out; goto out_free;
} }
} }
@ -1135,7 +1136,7 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
dsl_sync_task_create(dstg, dsl_dataset_destroy_check, dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
dsl_dataset_destroy_sync, &dsda, tag, 0); dsl_dataset_destroy_sync, &dsda, tag, 0);
dsl_sync_task_create(dstg, dsl_dir_destroy_check, dsl_sync_task_create(dstg, dsl_dir_destroy_check,
dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); dsl_dir_destroy_sync, dummy_ds, FTAG, 0);
err = dsl_sync_task_group_wait(dstg); err = dsl_sync_task_group_wait(dstg);
dsl_sync_task_group_destroy(dstg); dsl_sync_task_group_destroy(dstg);
@ -1158,6 +1159,9 @@ dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
/* if it is successful, dsl_dir_destroy_sync will close the dd */ /* if it is successful, dsl_dir_destroy_sync will close the dd */
if (err) if (err)
dsl_dir_close(dd, FTAG); dsl_dir_close(dd, FTAG);
out_free:
kmem_free(dummy_ds, sizeof (dsl_dataset_t));
out: out:
dsl_dataset_disown(ds, tag); dsl_dataset_disown(ds, tag);
return (err); return (err);