| Message ID | 20231212195255.219624-1-sidhartha.kumar@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [6.6.y] maple_tree: do not preallocate nodes for slot stores | expand |
On 12/12/23 11:52 AM, Sidhartha Kumar wrote: > mas_preallocate() defaults to requesting 1 node for preallocation and then > ,depending on the type of store, will update the request variable. There > isn't a check for a slot store type, so slot stores are preallocating the > default 1 node. Slot stores do not require any additional nodes, so add a > check for the slot store case that will bypass node_count_gfp(). Update > the tests to reflect that slot stores do not require allocations. > > User visible effects of this bug include increased memory usage from the > unneeded node that was allocated. > > Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") > Cc: <stable@vger.kernel.org> # 6.6+ > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> > --- > This is a modified backport as the patch to fix this in upstream does not > apply to 6.6 because the node_end field was moved from the ma_wr_state to > the ma_state after 6.6. Please disregard this patch, the upstream fix[1] does actually apply correctly to the 6.6 stable branch. Sorry for the noise, Sid [1] https://lore.kernel.org/linux-mm/20231213205058.386589-1-sidhartha.kumar@oracle.com/T/#u > lib/maple_tree.c | 6 ++++++ > tools/testing/radix-tree/maple.c | 2 +- > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > index bb24d84a4922f..5950d0c0e0f69 100644 > --- a/lib/maple_tree.c > +++ b/lib/maple_tree.c > @@ -5501,6 +5501,12 @@ int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp) > > mas_wr_end_piv(&wr_mas); > node_size = mas_wr_new_end(&wr_mas); > + > + /* Slot store, does not require additional nodes */ > + if ((node_size == wr_mas.node_end) && ((!mt_in_rcu(mas->tree)) > + || (wr_mas.offset_end - mas->offset == 1))) > + return 0; > + > if (node_size >= mt_slots[wr_mas.type]) { > /* Split, worst case for now. */ > request = 1 + mas_mt_height(mas) * 2; > diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c > index e5da1cad70baf..76a8990bb14e8 100644 > --- a/tools/testing/radix-tree/maple.c > +++ b/tools/testing/radix-tree/maple.c > @@ -35538,7 +35538,7 @@ static noinline void __init check_prealloc(struct maple_tree *mt) > MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0); > allocated = mas_allocated(&mas); > height = mas_mt_height(&mas); > - MT_BUG_ON(mt, allocated != 1); > + MT_BUG_ON(mt, allocated != 0); > mas_store_prealloc(&mas, ptr); > MT_BUG_ON(mt, mas_allocated(&mas) != 0); >
On Tue, Dec 12, 2023 at 11:52:55AM -0800, Sidhartha Kumar wrote: > mas_preallocate() defaults to requesting 1 node for preallocation and then > ,depending on the type of store, will update the request variable. There > isn't a check for a slot store type, so slot stores are preallocating the > default 1 node. Slot stores do not require any additional nodes, so add a > check for the slot store case that will bypass node_count_gfp(). Update > the tests to reflect that slot stores do not require allocations. > > User visible effects of this bug include increased memory usage from the > unneeded node that was allocated. > > Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") > Cc: <stable@vger.kernel.org> # 6.6+ > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> > --- > This is a modified backport as the patch to fix this in upstream does not > apply to 6.6 because the node_end field was moved from the ma_wr_state to > the ma_state after 6.6. What is the git commit id of this change in Linus's tree? thanks, greg k-h
On 12/18/23 2:59 AM, Greg KH wrote: > On Tue, Dec 12, 2023 at 11:52:55AM -0800, Sidhartha Kumar wrote: >> mas_preallocate() defaults to requesting 1 node for preallocation and then >> ,depending on the type of store, will update the request variable. There >> isn't a check for a slot store type, so slot stores are preallocating the >> default 1 node. Slot stores do not require any additional nodes, so add a >> check for the slot store case that will bypass node_count_gfp(). Update >> the tests to reflect that slot stores do not require allocations. >> >> User visible effects of this bug include increased memory usage from the >> unneeded node that was allocated. >> >> Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") >> Cc: <stable@vger.kernel.org> # 6.6+ >> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> >> --- >> This is a modified backport as the patch to fix this in upstream does not >> apply to 6.6 because the node_end field was moved from the ma_wr_state to >> the ma_state after 6.6. > > What is the git commit id of this change in Linus's tree? The patch is in akpm's mm-hotfixes-unstable tree and has not made it to Linus's tree yet. Thanks, Sid > > thanks, > > greg k-h
On Mon, Dec 18, 2023 at 09:53:53AM -0800, Sidhartha Kumar wrote: > On 12/18/23 2:59 AM, Greg KH wrote: > > On Tue, Dec 12, 2023 at 11:52:55AM -0800, Sidhartha Kumar wrote: > > > mas_preallocate() defaults to requesting 1 node for preallocation and then > > > ,depending on the type of store, will update the request variable. There > > > isn't a check for a slot store type, so slot stores are preallocating the > > > default 1 node. Slot stores do not require any additional nodes, so add a > > > check for the slot store case that will bypass node_count_gfp(). Update > > > the tests to reflect that slot stores do not require allocations. > > > > > > User visible effects of this bug include increased memory usage from the > > > unneeded node that was allocated. > > > > > > Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") > > > Cc: <stable@vger.kernel.org> # 6.6+ > > > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> > > > --- > > > This is a modified backport as the patch to fix this in upstream does not > > > apply to 6.6 because the node_end field was moved from the ma_wr_state to > > > the ma_state after 6.6. > > > > What is the git commit id of this change in Linus's tree? > > The patch is in akpm's mm-hotfixes-unstable tree and has not made it to > Linus's tree yet. Ok, please resend when it hits Linus's tree.
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index bb24d84a4922f..5950d0c0e0f69 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5501,6 +5501,12 @@ int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp) mas_wr_end_piv(&wr_mas); node_size = mas_wr_new_end(&wr_mas); + + /* Slot store, does not require additional nodes */ + if ((node_size == wr_mas.node_end) && ((!mt_in_rcu(mas->tree)) + || (wr_mas.offset_end - mas->offset == 1))) + return 0; + if (node_size >= mt_slots[wr_mas.type]) { /* Split, worst case for now. */ request = 1 + mas_mt_height(mas) * 2; diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index e5da1cad70baf..76a8990bb14e8 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -35538,7 +35538,7 @@ static noinline void __init check_prealloc(struct maple_tree *mt) MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0); allocated = mas_allocated(&mas); height = mas_mt_height(&mas); - MT_BUG_ON(mt, allocated != 1); + MT_BUG_ON(mt, allocated != 0); mas_store_prealloc(&mas, ptr); MT_BUG_ON(mt, mas_allocated(&mas) != 0);
mas_preallocate() defaults to requesting 1 node for preallocation and then ,depending on the type of store, will update the request variable. There isn't a check for a slot store type, so slot stores are preallocating the default 1 node. Slot stores do not require any additional nodes, so add a check for the slot store case that will bypass node_count_gfp(). Update the tests to reflect that slot stores do not require allocations. User visible effects of this bug include increased memory usage from the unneeded node that was allocated. Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") Cc: <stable@vger.kernel.org> # 6.6+ Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> --- This is a modified backport as the patch to fix this in upstream does not apply to 6.6 because the node_end field was moved from the ma_wr_state to the ma_state after 6.6. lib/maple_tree.c | 6 ++++++ tools/testing/radix-tree/maple.c | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-)