On Mon, Oct 23, 2023 at 09:40:16AM +0800, Guoqing Jiang wrote:
>
>
> On 10/15/23 17:19, Leon Romanovsky wrote:
> > On Thu, Oct 12, 2023 at 01:29:21AM -0700, Maxim Samoylov wrote:
> > > This patch provides the uniform handling for RLIM_INFINITY value
> > > across the infiniband/rdma subsystem.
> > >
> > > Currently in some cases the infinity constant is treated
> > > as an actual limit value, which could be misleading.
> > >
> > > Let's also provide the single helper to check against process
> > > MEMLOCK limit while registering user memory region mappings.
> > >
> > > Signed-off-by: Maxim Samoylov<max7255@xxxxxxxx>
> > > ---
> > >
> > > v1 -> v2: rewritten commit message, rebased on recent upstream
> > >
> > > drivers/infiniband/core/umem.c | 7 ++-----
> > > drivers/infiniband/hw/qib/qib_user_pages.c | 7 +++----
> > > drivers/infiniband/hw/usnic/usnic_uiom.c | 6 ++----
> > > drivers/infiniband/sw/siw/siw_mem.c | 6 +++---
> > > drivers/infiniband/sw/siw/siw_verbs.c | 23 ++++++++++------------
> > > include/rdma/ib_umem.h | 11 +++++++++++
> > > 6 files changed, 31 insertions(+), 29 deletions(-)
> > <...>
> >
> > > @@ -1321,8 +1322,8 @@ struct ib_mr *siw_reg_user_mr(struct ib_pd *pd, u64 start, u64 len,
> > > struct siw_umem *umem = NULL;
> > > struct siw_ureq_reg_mr ureq;
> > > struct siw_device *sdev = to_siw_dev(pd->device);
> > > -
> > > - unsigned long mem_limit = rlimit(RLIMIT_MEMLOCK);
> > > + unsigned long num_pages =
> > > + (PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT;
> > > int rv;
> > > siw_dbg_pd(pd, "start: 0x%pK, va: 0x%pK, len: %llu\n",
> > > @@ -1338,19 +1339,15 @@ struct ib_mr *siw_reg_user_mr(struct ib_pd *pd, u64 start, u64 len,
> > > rv = -EINVAL;
> > > goto err_out;
> > > }
> > > - if (mem_limit != RLIM_INFINITY) {
> > > - unsigned long num_pages =
> > > - (PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT;
> > > - mem_limit >>= PAGE_SHIFT;
> > > - if (num_pages > mem_limit - current->mm->locked_vm) {
> > > - siw_dbg_pd(pd, "pages req %lu, max %lu, lock %lu\n",
> > > - num_pages, mem_limit,
> > > - current->mm->locked_vm);
> > > - rv = -ENOMEM;
> > > - goto err_out;
> > > - }
> > > + if (!ib_umem_check_rlimit_memlock(num_pages + current->mm->locked_vm)) {
> > > + siw_dbg_pd(pd, "pages req %lu, max %lu, lock %lu\n",
> > > + num_pages, rlimit(RLIMIT_MEMLOCK),
> > > + current->mm->locked_vm);
> > > + rv = -ENOMEM;
> > > + goto err_out;
> > > }
> > Sorry for late response, but why does this hunk exist in first place?
> >
> > > +
> > > umem = siw_umem_get(start, len, ib_access_writable(rights));
> > This should be ib_umem_get().
>
> IMO, it deserves a separate patch, and replace siw_umem_get with ib_umem_get
> is not straightforward given siw_mem has two types of memory (pbl and umem).
The thing is that once you convince yourself that SIW should use ib_umem_get(),
the same question will arise for other parts of this patch where
ib_umem_check_rlimit_memlock() is used.
And if we eliminate them all, there won't be a need for this new API call at all.
Thanks
>
> Thanks,
> Guoqing
