Re: [PATCH v1 2/2] mm: memcg: introduce new event to trace shrink_memcg

From: Dmitry Rokosov
Date: Wed Nov 01 2023 - 13:54:09 EST


Oh, I apologize for that. It seems that I need to wrap the new
tracepoint calls with CONFIG_MEMCG. I will proceed to prepare the new
version.

On Wed, Nov 01, 2023 at 11:44:10PM +0800, kernel test robot wrote:
> Hi Dmitry,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on akpm-mm/mm-everything]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Dmitry-Rokosov/mm-memcg-print-out-cgroup-name-in-the-memcg-tracepoints/20231101-183040
> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/r/20231101102837.25205-3-ddrokosov%40salutedevices.com
> patch subject: [PATCH v1 2/2] mm: memcg: introduce new event to trace shrink_memcg
> config: um-allyesconfig (https://download.01.org/0day-ci/archive/20231101/202311012319.7ULVSdyR-lkp@xxxxxxxxx/config)
> compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231101/202311012319.7ULVSdyR-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202311012319.7ULVSdyR-lkp@xxxxxxxxx/
>
> All errors (new ones prefixed by >>):
>
> In file included from mm/vmscan.c:19:
> In file included from include/linux/kernel_stat.h:9:
> In file included from include/linux/interrupt.h:11:
> In file included from include/linux/hardirq.h:11:
> In file included from arch/um/include/asm/hardirq.h:5:
> In file included from include/asm-generic/hardirq.h:17:
> In file included from include/linux/irq.h:20:
> In file included from include/linux/io.h:13:
> In file included from arch/um/include/asm/io.h:24:
> include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> val = __raw_readb(PCI_IOBASE + addr);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
> ~~~~~~~~~~ ^
> include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
> #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
> ^
> In file included from mm/vmscan.c:19:
> In file included from include/linux/kernel_stat.h:9:
> In file included from include/linux/interrupt.h:11:
> In file included from include/linux/hardirq.h:11:
> In file included from arch/um/include/asm/hardirq.h:5:
> In file included from include/asm-generic/hardirq.h:17:
> In file included from include/linux/irq.h:20:
> In file included from include/linux/io.h:13:
> In file included from arch/um/include/asm/io.h:24:
> include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
> ~~~~~~~~~~ ^
> include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
> #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
> ^
> In file included from mm/vmscan.c:19:
> In file included from include/linux/kernel_stat.h:9:
> In file included from include/linux/interrupt.h:11:
> In file included from include/linux/hardirq.h:11:
> In file included from arch/um/include/asm/hardirq.h:5:
> In file included from include/asm-generic/hardirq.h:17:
> In file included from include/linux/irq.h:20:
> In file included from include/linux/io.h:13:
> In file included from arch/um/include/asm/io.h:24:
> include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> __raw_writeb(value, PCI_IOBASE + addr);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> readsb(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> readsw(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> readsl(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> writesb(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> writesw(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> writesl(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^
> >> mm/vmscan.c:5811:3: error: implicit declaration of function 'trace_mm_vmscan_memcg_shrink_begin' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> trace_mm_vmscan_memcg_shrink_begin(memcg,
> ^
> mm/vmscan.c:5811:3: note: did you mean 'trace_mm_vmscan_lru_shrink_active'?
> include/trace/events/vmscan.h:467:1: note: 'trace_mm_vmscan_lru_shrink_active' declared here
> TRACE_EVENT(mm_vmscan_lru_shrink_active,
> ^
> include/linux/tracepoint.h:566:2: note: expanded from macro 'TRACE_EVENT'
> DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
> ^
> include/linux/tracepoint.h:432:2: note: expanded from macro 'DECLARE_TRACE'
> __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
> ^
> include/linux/tracepoint.h:355:21: note: expanded from macro '__DECLARE_TRACE'
> static inline void trace_##name(proto) \
> ^
> <scratch space>:33:1: note: expanded from here
> trace_mm_vmscan_lru_shrink_active
> ^
> >> mm/vmscan.c:5845:3: error: implicit declaration of function 'trace_mm_vmscan_memcg_shrink_end' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> trace_mm_vmscan_memcg_shrink_end(memcg,
> ^
> mm/vmscan.c:5845:3: note: did you mean 'trace_mm_vmscan_memcg_shrink_begin'?
> mm/vmscan.c:5811:3: note: 'trace_mm_vmscan_memcg_shrink_begin' declared here
> trace_mm_vmscan_memcg_shrink_begin(memcg,
> ^
> 12 warnings and 2 errors generated.
>
>
> vim +/trace_mm_vmscan_memcg_shrink_begin +5811 mm/vmscan.c
>
> 5791
> 5792 static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
> 5793 {
> 5794 struct mem_cgroup *target_memcg = sc->target_mem_cgroup;
> 5795 struct mem_cgroup *memcg;
> 5796
> 5797 memcg = mem_cgroup_iter(target_memcg, NULL, NULL);
> 5798 do {
> 5799 struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat);
> 5800 unsigned long reclaimed;
> 5801 unsigned long scanned;
> 5802
> 5803 /*
> 5804 * This loop can become CPU-bound when target memcgs
> 5805 * aren't eligible for reclaim - either because they
> 5806 * don't have any reclaimable pages, or because their
> 5807 * memory is explicitly protected. Avoid soft lockups.
> 5808 */
> 5809 cond_resched();
> 5810
> > 5811 trace_mm_vmscan_memcg_shrink_begin(memcg,
> 5812 sc->order,
> 5813 sc->gfp_mask);
> 5814
> 5815 mem_cgroup_calculate_protection(target_memcg, memcg);
> 5816
> 5817 if (mem_cgroup_below_min(target_memcg, memcg)) {
> 5818 /*
> 5819 * Hard protection.
> 5820 * If there is no reclaimable memory, OOM.
> 5821 */
> 5822 continue;
> 5823 } else if (mem_cgroup_below_low(target_memcg, memcg)) {
> 5824 /*
> 5825 * Soft protection.
> 5826 * Respect the protection only as long as
> 5827 * there is an unprotected supply
> 5828 * of reclaimable memory from other cgroups.
> 5829 */
> 5830 if (!sc->memcg_low_reclaim) {
> 5831 sc->memcg_low_skipped = 1;
> 5832 continue;
> 5833 }
> 5834 memcg_memory_event(memcg, MEMCG_LOW);
> 5835 }
> 5836
> 5837 reclaimed = sc->nr_reclaimed;
> 5838 scanned = sc->nr_scanned;
> 5839
> 5840 shrink_lruvec(lruvec, sc);
> 5841
> 5842 shrink_slab(sc->gfp_mask, pgdat->node_id, memcg,
> 5843 sc->priority);
> 5844
> > 5845 trace_mm_vmscan_memcg_shrink_end(memcg,
> 5846 sc->nr_reclaimed - reclaimed);
> 5847
> 5848 /* Record the group's reclaim efficiency */
> 5849 if (!sc->proactive)
> 5850 vmpressure(sc->gfp_mask, memcg, false,
> 5851 sc->nr_scanned - scanned,
> 5852 sc->nr_reclaimed - reclaimed);
> 5853
> 5854 } while ((memcg = mem_cgroup_iter(target_memcg, memcg, NULL)));
> 5855 }
> 5856
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

--
Thank you,
Dmitry