On 11/6/26 14:18, Tao Cui wrote: > From: Tao Cui <[email protected]> > > udmabuf pins the pages of a memfd and hands them out as a dma-buf. The > data pages keep the accounting of the memfd they were instantiated in, > but the bookkeeping around them does not: the page pointer array and > the pinned_folios array, both sized by the buffer page count, plus the > transient folios array sized by the memfd folio count, are plain > GFP_KERNEL. A 1GB buffer costs about 4MB of uncharged SUnreclaim > memory, and size_limit_mb defaults to INT_MAX. > > Charge the three kvmalloc allocations so the creator pays for the > metadata it induces. The system heap in the same subsystem already > accounts its buffer allocation; the data pages here stay with the > memfd.
T.J. needs to take a look here, but I fear that this might break uAPI. A lot of the DMA-buf resources are intentionally not charged against memcg. Regards, Christian. > > Signed-off-by: Tao Cui <[email protected]> > --- > drivers/dma-buf/udmabuf.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c > index df6dd0046242..40182c82df6b 100644 > --- a/drivers/dma-buf/udmabuf.c > +++ b/drivers/dma-buf/udmabuf.c > @@ -190,11 +190,12 @@ static void unpin_all_folios(struct udmabuf *ubuf) > > static __always_inline int init_udmabuf(struct udmabuf *ubuf, pgoff_t pgcnt) > { > - ubuf->pages = kvmalloc_objs(*ubuf->pages, pgcnt); > + ubuf->pages = kvmalloc_objs(*ubuf->pages, pgcnt, GFP_KERNEL_ACCOUNT); > if (!ubuf->pages) > return -ENOMEM; > > - ubuf->pinned_folios = kvmalloc_objs(*ubuf->pinned_folios, pgcnt); > + ubuf->pinned_folios = kvmalloc_objs(*ubuf->pinned_folios, pgcnt, > + GFP_KERNEL_ACCOUNT); > if (!ubuf->pinned_folios) > return -ENOMEM; > > @@ -387,7 +388,7 @@ static long udmabuf_create(struct miscdevice *device, > if (ret) > goto err; > > - folios = kvmalloc_objs(*folios, max_nr_folios); > + folios = kvmalloc_objs(*folios, max_nr_folios, GFP_KERNEL_ACCOUNT); > if (!folios) { > ret = -ENOMEM; > goto err; > -- > 2.43.0 >
