On 23/10/2023 07:52, Leon Romanovsky wrote:
> 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?
>>>
Trailing newline, will definitely drop it.
>>>> +
>>>> 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
>
Hi!
So, as for 31.10.2023 I still see siw_umem_get() call used in
linux-rdma repo in "for-next" branch.
AFAIU this helper call is used only in a single place and could
potentially be replaced with ib_umem_get() as Leon suggests.
But should we perform it right inside this memlock helper patch?
I can submit later another patch with siw_umem_get() replaced
if necessary.
>>
>> Thanks,
>> Guoqing
