Re: [PATCH v20 02/20] mm/memcg: bail early from swap accounting if memcg disabled
在 2020/10/30 下午10:04, Johannes Weiner 写道: >>> Acked-by: Johannes Weiner >>> >>> This should go in before the previous patch that adds the WARN for it. >> Right, but than the long ops may not weird. Should I remove the ops and >> resend the whole patchset? > You mean the warning in the changelog? I think that's alright. You can > just say that you're about to remove the !page->memcg check in the > next patch because the original reasons for having it are gone, and > memcg being disabled is the only remaining exception, so this patch > makes that check explicit in preparation for the next. > > Sorry, it's all a bit of a hassle, I just wouldn't want to introduce a > known warning into the kernel between those two patches (could confuse > bisection runs, complicates partial reverts etc.) H Johannes, I see, I will exchange the 1st and 2nd patch place with above comments in commit log. I guess you could give more comments on other patches, so I am going to wait you for more comments and send v21 as a whole. :) Many thanks! Alex
Re: [PATCH v20 02/20] mm/memcg: bail early from swap accounting if memcg disabled
On Fri, Oct 30, 2020 at 10:27:51AM +0800, Alex Shi wrote: > > > 在 2020/10/29 下午9:46, Johannes Weiner 写道: > >> ? release_pages+0x1ae/0x410 > >> shmem_alloc_and_acct_page+0x77/0x1c0 > >> shmem_getpage_gfp+0x162/0x910 > >> shmem_fault+0x74/0x210 > >> ? filemap_map_pages+0x29c/0x410 > >> __do_fault+0x37/0x190 > >> handle_mm_fault+0x120a/0x1770 > >> exc_page_fault+0x251/0x450 > >> ? asm_exc_page_fault+0x8/0x30 > >> asm_exc_page_fault+0x1e/0x30 > >> > >> Signed-off-by: Alex Shi > >> Reviewed-by: Roman Gushchin > >> Acked-by: Michal Hocko > >> Acked-by: Hugh Dickins > >> Cc: Johannes Weiner > >> Cc: Michal Hocko > >> Cc: Vladimir Davydov > >> Cc: Andrew Morton > >> Cc: cgro...@vger.kernel.org > >> Cc: linux...@kvack.org > >> Cc: linux-kernel@vger.kernel.org > > Acked-by: Johannes Weiner > > > > This should go in before the previous patch that adds the WARN for it. > > Right, but than the long ops may not weird. Should I remove the ops and > resend the whole patchset? You mean the warning in the changelog? I think that's alright. You can just say that you're about to remove the !page->memcg check in the next patch because the original reasons for having it are gone, and memcg being disabled is the only remaining exception, so this patch makes that check explicit in preparation for the next. Sorry, it's all a bit of a hassle, I just wouldn't want to introduce a known warning into the kernel between those two patches (could confuse bisection runs, complicates partial reverts etc.)
Re: [PATCH v20 02/20] mm/memcg: bail early from swap accounting if memcg disabled
在 2020/10/29 下午9:46, Johannes Weiner 写道: >> ? release_pages+0x1ae/0x410 >> shmem_alloc_and_acct_page+0x77/0x1c0 >> shmem_getpage_gfp+0x162/0x910 >> shmem_fault+0x74/0x210 >> ? filemap_map_pages+0x29c/0x410 >> __do_fault+0x37/0x190 >> handle_mm_fault+0x120a/0x1770 >> exc_page_fault+0x251/0x450 >> ? asm_exc_page_fault+0x8/0x30 >> asm_exc_page_fault+0x1e/0x30 >> >> Signed-off-by: Alex Shi >> Reviewed-by: Roman Gushchin >> Acked-by: Michal Hocko >> Acked-by: Hugh Dickins >> Cc: Johannes Weiner >> Cc: Michal Hocko >> Cc: Vladimir Davydov >> Cc: Andrew Morton >> Cc: cgro...@vger.kernel.org >> Cc: linux...@kvack.org >> Cc: linux-kernel@vger.kernel.org > Acked-by: Johannes Weiner > > This should go in before the previous patch that adds the WARN for it. Right, but than the long ops may not weird. Should I remove the ops and resend the whole patchset? Which way is convenient for you? Thanks Alex
Re: [PATCH v20 02/20] mm/memcg: bail early from swap accounting if memcg disabled
On Thu, Oct 29, 2020 at 06:44:47PM +0800, Alex Shi wrote: > If we disabled memcg by cgroup_disable=memory, page->memcg will be NULL > and so the charge is skipped and that will trigger a warning like below. > Let's return from the funcs earlier. > > anon flags:0x5005b48008000d(locked|uptodate|dirty|swapbacked) > raw: 005005b48008000d dead0100 dead0122 8897c7c76ad1 > raw: 0022 0002 > page dumped because: VM_WARN_ON_ONCE_PAGE(!memcg) > ... > RIP: 0010:vprintk_emit+0x1f7/0x260 > Code: 00 84 d2 74 72 0f b6 15 27 58 64 01 48 c7 c0 00 d4 72 82 84 d2 74 09 > f3 90 0f b6 10 84 d2 75 f7 e8 de 0d 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 e9 > 62 ff ff ff 80 3d 88 c9 3a 01 00 0f 85 54 fe ff > RSP: 0018:c9000faab358 EFLAGS: 0202 > RAX: 8272d400 RBX: 005e RCX: 88afd80d0040 > RDX: RSI: 0002 RDI: 0202 > RBP: c9000faab3a8 R08: 8272d440 R09: 00022480 > R10: 00120c77be68bfac R11: 00cd7568 R12: 0202 > R13: 0057c0080005 R14: 820a0130 R15: c9000faab3e8 > ? vprintk_emit+0x140/0x260 > vprintk_default+0x1a/0x20 > vprintk_func+0x4f/0xc4 > ? vprintk_func+0x4f/0xc4 > printk+0x53/0x6a > ? xas_load+0xc/0x80 > __dump_page.cold.6+0xff/0x4ee > ? xas_init_marks+0x23/0x50 > ? xas_store+0x30/0x40 > ? free_swap_slot+0x43/0xd0 > ? put_swap_page+0x119/0x320 > ? update_load_avg+0x82/0x580 > dump_page+0x9/0xb > mem_cgroup_try_charge_swap+0x16e/0x1d0 > get_swap_page+0x130/0x210 > add_to_swap+0x41/0xc0 > shrink_page_list+0x99e/0xdf0 > shrink_inactive_list+0x199/0x360 > shrink_lruvec+0x40d/0x650 > ? _cond_resched+0x14/0x30 > ? _cond_resched+0x14/0x30 > shrink_node+0x226/0x6e0 > do_try_to_free_pages+0xd0/0x400 > try_to_free_pages+0xef/0x130 > __alloc_pages_slowpath.constprop.127+0x38d/0xbd0 > ? ___slab_alloc+0x31d/0x6f0 > __alloc_pages_nodemask+0x27f/0x2c0 > alloc_pages_vma+0x75/0x220 > shmem_alloc_page+0x46/0x90 > ? release_pages+0x1ae/0x410 > shmem_alloc_and_acct_page+0x77/0x1c0 > shmem_getpage_gfp+0x162/0x910 > shmem_fault+0x74/0x210 > ? filemap_map_pages+0x29c/0x410 > __do_fault+0x37/0x190 > handle_mm_fault+0x120a/0x1770 > exc_page_fault+0x251/0x450 > ? asm_exc_page_fault+0x8/0x30 > asm_exc_page_fault+0x1e/0x30 > > Signed-off-by: Alex Shi > Reviewed-by: Roman Gushchin > Acked-by: Michal Hocko > Acked-by: Hugh Dickins > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: Vladimir Davydov > Cc: Andrew Morton > Cc: cgro...@vger.kernel.org > Cc: linux...@kvack.org > Cc: linux-kernel@vger.kernel.org Acked-by: Johannes Weiner This should go in before the previous patch that adds the WARN for it.
[PATCH v20 02/20] mm/memcg: bail early from swap accounting if memcg disabled
If we disabled memcg by cgroup_disable=memory, page->memcg will be NULL and so the charge is skipped and that will trigger a warning like below. Let's return from the funcs earlier. anon flags:0x5005b48008000d(locked|uptodate|dirty|swapbacked) raw: 005005b48008000d dead0100 dead0122 8897c7c76ad1 raw: 0022 0002 page dumped because: VM_WARN_ON_ONCE_PAGE(!memcg) ... RIP: 0010:vprintk_emit+0x1f7/0x260 Code: 00 84 d2 74 72 0f b6 15 27 58 64 01 48 c7 c0 00 d4 72 82 84 d2 74 09 f3 90 0f b6 10 84 d2 75 f7 e8 de 0d 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 e9 62 ff ff ff 80 3d 88 c9 3a 01 00 0f 85 54 fe ff RSP: 0018:c9000faab358 EFLAGS: 0202 RAX: 8272d400 RBX: 005e RCX: 88afd80d0040 RDX: RSI: 0002 RDI: 0202 RBP: c9000faab3a8 R08: 8272d440 R09: 00022480 R10: 00120c77be68bfac R11: 00cd7568 R12: 0202 R13: 0057c0080005 R14: 820a0130 R15: c9000faab3e8 ? vprintk_emit+0x140/0x260 vprintk_default+0x1a/0x20 vprintk_func+0x4f/0xc4 ? vprintk_func+0x4f/0xc4 printk+0x53/0x6a ? xas_load+0xc/0x80 __dump_page.cold.6+0xff/0x4ee ? xas_init_marks+0x23/0x50 ? xas_store+0x30/0x40 ? free_swap_slot+0x43/0xd0 ? put_swap_page+0x119/0x320 ? update_load_avg+0x82/0x580 dump_page+0x9/0xb mem_cgroup_try_charge_swap+0x16e/0x1d0 get_swap_page+0x130/0x210 add_to_swap+0x41/0xc0 shrink_page_list+0x99e/0xdf0 shrink_inactive_list+0x199/0x360 shrink_lruvec+0x40d/0x650 ? _cond_resched+0x14/0x30 ? _cond_resched+0x14/0x30 shrink_node+0x226/0x6e0 do_try_to_free_pages+0xd0/0x400 try_to_free_pages+0xef/0x130 __alloc_pages_slowpath.constprop.127+0x38d/0xbd0 ? ___slab_alloc+0x31d/0x6f0 __alloc_pages_nodemask+0x27f/0x2c0 alloc_pages_vma+0x75/0x220 shmem_alloc_page+0x46/0x90 ? release_pages+0x1ae/0x410 shmem_alloc_and_acct_page+0x77/0x1c0 shmem_getpage_gfp+0x162/0x910 shmem_fault+0x74/0x210 ? filemap_map_pages+0x29c/0x410 __do_fault+0x37/0x190 handle_mm_fault+0x120a/0x1770 exc_page_fault+0x251/0x450 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 Signed-off-by: Alex Shi Reviewed-by: Roman Gushchin Acked-by: Michal Hocko Acked-by: Hugh Dickins Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Andrew Morton Cc: cgro...@vger.kernel.org Cc: linux...@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/memcontrol.c | 6 ++ 1 file changed, 6 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6b67da305958..e46b9f9501c2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7169,6 +7169,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) VM_BUG_ON_PAGE(PageLRU(page), page); VM_BUG_ON_PAGE(page_count(page), page); + if (mem_cgroup_disabled()) + return; + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) return; @@ -7233,6 +7236,9 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) struct mem_cgroup *memcg; unsigned short oldid; + if (mem_cgroup_disabled()) + return 0; + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) return 0; -- 1.8.3.1
