Re: [PATCH v7 rdma-next 0/7] RDMA/qedr: Use the doorbell overflow recovery mechanism for RDMA

[Gal Pressman <galpress@amazon.com>]

On 20/08/2019 15:18, Michal Kalderon wrote:
> This patch series uses the doorbell overflow recovery mechanism
> introduced in
> commit 36907cd5cd72 ("qed: Add doorbell overflow recovery mechanism")
> for rdma ( RoCE and iWARP )
> 
> The first five patches modify the core code to contain helper
> functions for managing mmap_xa inserting, getting and freeing
> entries. The code was based on the code from efa driver.
> There is still an open discussion on whether we should take
> this even further and make the entire mmap generic. Until a
> decision is made, I only created the database API and modified
> the efa, qedr, siw driver to use it. The functions are integrated
> witht the umap mechanism.
> 
> The doorbell recovery code is based on the common code.
> 
> Efa driver was compile tested and checked only modprobe/rmmod.
> SIW was compile tested only

Hey Michal,

I haven't had the time to review the patches yet, but I did run it through our
regression and got some dmesg call traces [1].
There are also some kmemleak warnings for suspected memory leaks, don't have the
full information ATM but I can try and extract it if needed.

Thanks!

[1] (this is the first trace of many)
BUG: Bad page state in process ib_send_bw  pfn:1411f76
page:ffffea005047dd80 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffe000000000()
raw: 002fffe000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000
page dumped because: nonzero _refcount
Modules linked in: sunrpc dm_mirror dm_region_hash dm_log dm_mod efa ib_uverbs
ib_core crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 crypto_simd
cryptd glue_helper button pcspkr evdev ip_tables x_tables xfs libcrc32c nvme
crc32c_intel nvme_core ena ipv6 crc_ccitt nf_defrag_ipv6 autofs4
CPU: 29 PID: 62474 Comm: ib_send_bw Not tainted 5.3.0-rc1-dirty #1
Hardware name: Amazon EC2 c5n.18xlarge/, BIOS 1.0 10/16/2017
Call Trace:
 dump_stack+0x9a/0xeb
 bad_page+0x104/0x180
 free_pcppages_bulk+0x31b/0xdd0
 ? uncharge_batch+0x1d2/0x2b0
 ? free_compound_page+0x40/0x40
 ? free_unref_page_commit+0x152/0x1b0
 free_unref_page_list+0x1b8/0x3e0
 release_pages+0x4c6/0x620
 ? put_pages_list+0xf0/0xf0
 ? free_pages_and_swap_cache+0x97/0x140
 tlb_flush_mmu+0x7a/0x280
 tlb_finish_mmu+0x44/0x170
 exit_mmap+0x147/0x2b0
 ? do_munmap+0x10/0x10
 mmput+0xb4/0x1d0
 do_exit+0x4c2/0x14d0
 ? mm_update_next_owner+0x360/0x360
 ? ktime_get_coarse_real_ts64+0xc0/0x120
 ? syscall_trace_enter+0x22d/0x5f0
 ? __audit_syscall_exit+0x31e/0x460
 ? syscall_slow_exit_work+0x2c0/0x2c0
 ? kfree+0x221/0x290
 ? mark_held_locks+0x1c/0xa0
 do_group_exit+0x6f/0x140
 __x64_sys_exit_group+0x28/0x30
 do_syscall_64+0x68/0x290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f6072a3b928
Code: Bad RIP value.
RSP: 002b:00007ffe4e09ae68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6072a3b928
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007f6072d24898 R08: 00000000000000e7 R09: ffffffffffffff70
R10: 00007f60724ead68 R11: 0000000000000246 R12: 00007f6072d24898
R13: 00007f6072d29d80 R14: 0000000000000000 R15: 0000000000000000
Disabling lock debugging due to kernel taint