| Message ID | 20230425110511.11680-4-zhangpeng.00@bytedance.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fix, rework and clean up for maple tree | expand |
* Peng Zhang <zhangpeng.00@bytedance.com> [230425 07:05]: > Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area() > and mas_empty_area_rev() respectively for allocation to reduce code > redundancy. And after doing this, we don't need to maintain two logically > identical codes to improve maintainability. > > In fact, mtree_alloc_range/rrange() has some bugs. For example, when > dealing with min equals to max (mas_empty_area/area_rev() has been fixed), > the allocation will fail. > There are still some other bugs in it, I saw it with my naked eyes, but > I didn't test it, for example: > When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min, > mas.last = max - size. However, mas_awalk() requires mas.index = min, > mas.last = max, which may lead to allocation failures. Please don't re-state code in your commit messages. Try to focus on what you did, and not why. ie: Aligned mtree_alloc_range() to use the same internal function as mas_empty_area(). > > Right now no users are using these two functions so the bug won't trigger, > but this might trigger in the future. > > Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any > difference between them. Yeah, evolution of the code converged on the same design. Thanks for seeing this. > > After doing this, we no longer need the three functions > mas_fill_gap(), mas_alloc(), and mas_rev_alloc(). Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and whatever else you found here. They were planned to simplify the mmap code allocations, but since there would need to be arch involvement (coloring, etc) and alignment, etc; it is better to leave this job to the mm code itself. > > Fixes: 54a611b60590 ("Maple Tree: add new data structure") > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> > --- > lib/maple_tree.c | 45 ++++++++++++--------------------------------- > 1 file changed, 12 insertions(+), 33 deletions(-) > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > index aa55c914818a0..294d4c8668323 100644 > --- a/lib/maple_tree.c > +++ b/lib/maple_tree.c > @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, > { > int ret = 0; > > - MA_STATE(mas, mt, min, max - size); > + MA_STATE(mas, mt, 0, 0); > if (!mt_is_alloc(mt)) > return -EINVAL; > > if (WARN_ON_ONCE(mt_is_reserved(entry))) > return -EINVAL; > > - if (min > max) > - return -EINVAL; > - > - if (max < size) > - return -EINVAL; > - > - if (!size) > - return -EINVAL; > - > mtree_lock(mt); > -retry: > - mas.offset = 0; > - mas.index = min; > - mas.last = max - size; > - ret = mas_alloc(&mas, entry, size, startp); > - if (mas_nomem(&mas, gfp)) > - goto retry; > - > + ret = mas_empty_area(&mas, min, max, size); > + if (!ret) > + ret = mas_store_gfp(&mas, entry, gfp); > mtree_unlock(mt); > + if (!ret) > + *startp = mas.index; > return ret; > } > EXPORT_SYMBOL(mtree_alloc_range); > @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp, > { > int ret = 0; > > - MA_STATE(mas, mt, min, max - size); > + MA_STATE(mas, mt, 0, 0); > if (!mt_is_alloc(mt)) > return -EINVAL; > > if (WARN_ON_ONCE(mt_is_reserved(entry))) > return -EINVAL; > > - if (min >= max) > - return -EINVAL; > - > - if (max < size - 1) > - return -EINVAL; > - > - if (!size) > - return -EINVAL; > - > mtree_lock(mt); > -retry: > - ret = mas_rev_alloc(&mas, min, max, entry, size, startp); > - if (mas_nomem(&mas, gfp)) > - goto retry; > - > + ret = mas_empty_area_rev(&mas, min, max, size); > + if (!ret) > + ret = mas_store_gfp(&mas, entry, gfp); > mtree_unlock(mt); > + if (!ret) > + *startp = mas.index; > return ret; > } > EXPORT_SYMBOL(mtree_alloc_rrange); > -- > 2.20.1 >
在 2023/4/26 00:08, Liam R. Howlett 写道: > * Peng Zhang <zhangpeng.00@bytedance.com> [230425 07:05]: >> Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area() >> and mas_empty_area_rev() respectively for allocation to reduce code >> redundancy. And after doing this, we don't need to maintain two logically >> identical codes to improve maintainability. >> >> In fact, mtree_alloc_range/rrange() has some bugs. For example, when >> dealing with min equals to max (mas_empty_area/area_rev() has been fixed), >> the allocation will fail. >> There are still some other bugs in it, I saw it with my naked eyes, but >> I didn't test it, for example: >> When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min, >> mas.last = max - size. However, mas_awalk() requires mas.index = min, >> mas.last = max, which may lead to allocation failures. > > Please don't re-state code in your commit messages. > > Try to focus on what you did, and not why. > > ie: Aligned mtree_alloc_range() to use the same internal function as > mas_empty_area(). > >> >> Right now no users are using these two functions so the bug won't trigger, >> but this might trigger in the future. >> >> Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any >> difference between them. > > Yeah, evolution of the code converged on the same design. Thanks for > seeing this. > >> >> After doing this, we no longer need the three functions >> mas_fill_gap(), mas_alloc(), and mas_rev_alloc(). > > Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and > whatever else you found here. They were planned to simplify the mmap > code allocations, but since there would need to be arch involvement > (coloring, etc) and alignment, etc; it is better to leave this job to > the mm code itself. Ok, I will remove some useless functions here. But mtree_alloc_range() and mtree_alloc_rrange() really don't need to be reserved? Because I don't know if there will be users using it in other scenarios in the future. Thank you for all your suggestions on this patch set, I will update them. > >> >> Fixes: 54a611b60590 ("Maple Tree: add new data structure") >> Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> >> --- >> lib/maple_tree.c | 45 ++++++++++++--------------------------------- >> 1 file changed, 12 insertions(+), 33 deletions(-) >> >> diff --git a/lib/maple_tree.c b/lib/maple_tree.c >> index aa55c914818a0..294d4c8668323 100644 >> --- a/lib/maple_tree.c >> +++ b/lib/maple_tree.c >> @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, >> { >> int ret = 0; >> >> - MA_STATE(mas, mt, min, max - size); >> + MA_STATE(mas, mt, 0, 0); >> if (!mt_is_alloc(mt)) >> return -EINVAL; >> >> if (WARN_ON_ONCE(mt_is_reserved(entry))) >> return -EINVAL; >> >> - if (min > max) >> - return -EINVAL; >> - >> - if (max < size) >> - return -EINVAL; >> - >> - if (!size) >> - return -EINVAL; >> - >> mtree_lock(mt); >> -retry: >> - mas.offset = 0; >> - mas.index = min; >> - mas.last = max - size; >> - ret = mas_alloc(&mas, entry, size, startp); >> - if (mas_nomem(&mas, gfp)) >> - goto retry; >> - >> + ret = mas_empty_area(&mas, min, max, size); >> + if (!ret) >> + ret = mas_store_gfp(&mas, entry, gfp); >> mtree_unlock(mt); >> + if (!ret) >> + *startp = mas.index; >> return ret; >> } >> EXPORT_SYMBOL(mtree_alloc_range); >> @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp, >> { >> int ret = 0; >> >> - MA_STATE(mas, mt, min, max - size); >> + MA_STATE(mas, mt, 0, 0); >> if (!mt_is_alloc(mt)) >> return -EINVAL; >> >> if (WARN_ON_ONCE(mt_is_reserved(entry))) >> return -EINVAL; >> >> - if (min >= max) >> - return -EINVAL; >> - >> - if (max < size - 1) >> - return -EINVAL; >> - >> - if (!size) >> - return -EINVAL; >> - >> mtree_lock(mt); >> -retry: >> - ret = mas_rev_alloc(&mas, min, max, entry, size, startp); >> - if (mas_nomem(&mas, gfp)) >> - goto retry; >> - >> + ret = mas_empty_area_rev(&mas, min, max, size); >> + if (!ret) >> + ret = mas_store_gfp(&mas, entry, gfp); >> mtree_unlock(mt); >> + if (!ret) >> + *startp = mas.index; >> return ret; >> } >> EXPORT_SYMBOL(mtree_alloc_rrange); >> -- >> 2.20.1 >>
* Peng Zhang <perlyzhang@gmail.com> [230426 08:34]: > > > 在 2023/4/26 00:08, Liam R. Howlett 写道: > > * Peng Zhang <zhangpeng.00@bytedance.com> [230425 07:05]: > > > Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area() > > > and mas_empty_area_rev() respectively for allocation to reduce code > > > redundancy. And after doing this, we don't need to maintain two logically > > > identical codes to improve maintainability. > > > > > > In fact, mtree_alloc_range/rrange() has some bugs. For example, when > > > dealing with min equals to max (mas_empty_area/area_rev() has been fixed), > > > the allocation will fail. > > > There are still some other bugs in it, I saw it with my naked eyes, but > > > I didn't test it, for example: > > > When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min, > > > mas.last = max - size. However, mas_awalk() requires mas.index = min, > > > mas.last = max, which may lead to allocation failures. > > > > Please don't re-state code in your commit messages. > > > > Try to focus on what you did, and not why. > > > > ie: Aligned mtree_alloc_range() to use the same internal function as > > mas_empty_area(). > > > > > > > > Right now no users are using these two functions so the bug won't trigger, > > > but this might trigger in the future. > > > > > > Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any > > > difference between them. > > > > Yeah, evolution of the code converged on the same design. Thanks for > > seeing this. > > > > > > > > After doing this, we no longer need the three functions > > > mas_fill_gap(), mas_alloc(), and mas_rev_alloc(). > > > > Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and > > whatever else you found here. They were planned to simplify the mmap > > code allocations, but since there would need to be arch involvement > > (coloring, etc) and alignment, etc; it is better to leave this job to > > the mm code itself. > Ok, I will remove some useless functions here. > But mtree_alloc_range() and mtree_alloc_rrange() really don't need to be > reserved? Because I don't know if there will be users using it in other > scenarios in the future. As you showed, a lot of the code is now the same elsewhere, so it wouldn't take much to make a version of this outside of the tree if someone needs the functionality. > > Thank you for all your suggestions on this patch set, I will update them. > > > > > > > > Fixes: 54a611b60590 ("Maple Tree: add new data structure") > > > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> > > > --- > > > lib/maple_tree.c | 45 ++++++++++++--------------------------------- > > > 1 file changed, 12 insertions(+), 33 deletions(-) > > > > > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > > > index aa55c914818a0..294d4c8668323 100644 > > > --- a/lib/maple_tree.c > > > +++ b/lib/maple_tree.c > > > @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, > > > { > > > int ret = 0; > > > - MA_STATE(mas, mt, min, max - size); > > > + MA_STATE(mas, mt, 0, 0); > > > if (!mt_is_alloc(mt)) > > > return -EINVAL; > > > if (WARN_ON_ONCE(mt_is_reserved(entry))) > > > return -EINVAL; > > > - if (min > max) > > > - return -EINVAL; > > > - > > > - if (max < size) > > > - return -EINVAL; > > > - > > > - if (!size) > > > - return -EINVAL; > > > - > > > mtree_lock(mt); > > > -retry: > > > - mas.offset = 0; > > > - mas.index = min; > > > - mas.last = max - size; > > > - ret = mas_alloc(&mas, entry, size, startp); > > > - if (mas_nomem(&mas, gfp)) > > > - goto retry; > > > - > > > + ret = mas_empty_area(&mas, min, max, size); > > > + if (!ret) > > > + ret = mas_store_gfp(&mas, entry, gfp); > > > mtree_unlock(mt); > > > + if (!ret) > > > + *startp = mas.index; > > > return ret; > > > } > > > EXPORT_SYMBOL(mtree_alloc_range); > > > @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp, > > > { > > > int ret = 0; > > > - MA_STATE(mas, mt, min, max - size); > > > + MA_STATE(mas, mt, 0, 0); > > > if (!mt_is_alloc(mt)) > > > return -EINVAL; > > > if (WARN_ON_ONCE(mt_is_reserved(entry))) > > > return -EINVAL; > > > - if (min >= max) > > > - return -EINVAL; > > > - > > > - if (max < size - 1) > > > - return -EINVAL; > > > - > > > - if (!size) > > > - return -EINVAL; > > > - > > > mtree_lock(mt); > > > -retry: > > > - ret = mas_rev_alloc(&mas, min, max, entry, size, startp); > > > - if (mas_nomem(&mas, gfp)) > > > - goto retry; > > > - > > > + ret = mas_empty_area_rev(&mas, min, max, size); > > > + if (!ret) > > > + ret = mas_store_gfp(&mas, entry, gfp); > > > mtree_unlock(mt); > > > + if (!ret) > > > + *startp = mas.index; > > > return ret; > > > } > > > EXPORT_SYMBOL(mtree_alloc_rrange); > > > -- > > > 2.20.1 > > >
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index aa55c914818a0..294d4c8668323 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, { int ret = 0; - MA_STATE(mas, mt, min, max - size); + MA_STATE(mas, mt, 0, 0); if (!mt_is_alloc(mt)) return -EINVAL; if (WARN_ON_ONCE(mt_is_reserved(entry))) return -EINVAL; - if (min > max) - return -EINVAL; - - if (max < size) - return -EINVAL; - - if (!size) - return -EINVAL; - mtree_lock(mt); -retry: - mas.offset = 0; - mas.index = min; - mas.last = max - size; - ret = mas_alloc(&mas, entry, size, startp); - if (mas_nomem(&mas, gfp)) - goto retry; - + ret = mas_empty_area(&mas, min, max, size); + if (!ret) + ret = mas_store_gfp(&mas, entry, gfp); mtree_unlock(mt); + if (!ret) + *startp = mas.index; return ret; } EXPORT_SYMBOL(mtree_alloc_range); @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp, { int ret = 0; - MA_STATE(mas, mt, min, max - size); + MA_STATE(mas, mt, 0, 0); if (!mt_is_alloc(mt)) return -EINVAL; if (WARN_ON_ONCE(mt_is_reserved(entry))) return -EINVAL; - if (min >= max) - return -EINVAL; - - if (max < size - 1) - return -EINVAL; - - if (!size) - return -EINVAL; - mtree_lock(mt); -retry: - ret = mas_rev_alloc(&mas, min, max, entry, size, startp); - if (mas_nomem(&mas, gfp)) - goto retry; - + ret = mas_empty_area_rev(&mas, min, max, size); + if (!ret) + ret = mas_store_gfp(&mas, entry, gfp); mtree_unlock(mt); + if (!ret) + *startp = mas.index; return ret; } EXPORT_SYMBOL(mtree_alloc_rrange);
Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area() and mas_empty_area_rev() respectively for allocation to reduce code redundancy. And after doing this, we don't need to maintain two logically identical codes to improve maintainability. In fact, mtree_alloc_range/rrange() has some bugs. For example, when dealing with min equals to max (mas_empty_area/area_rev() has been fixed), the allocation will fail. There are still some other bugs in it, I saw it with my naked eyes, but I didn't test it, for example: When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min, mas.last = max - size. However, mas_awalk() requires mas.index = min, mas.last = max, which may lead to allocation failures. Right now no users are using these two functions so the bug won't trigger, but this might trigger in the future. Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any difference between them. After doing this, we no longer need the three functions mas_fill_gap(), mas_alloc(), and mas_rev_alloc(). Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> --- lib/maple_tree.c | 45 ++++++++++++--------------------------------- 1 file changed, 12 insertions(+), 33 deletions(-)