From 55ab834a86a9934c4f17825c115f7dc16a89aae7 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 16 Dec 2022 10:46:33 +0100 Subject: Revert "mm: add nodes= arg to memory.reclaim" This reverts commit 12a5d3955227b0d7e04fb793ccceeb2a1dd275c5. Although it is recognized that a finer grained pro-active reclaim is something we need and want the semantic of this implementation is really ambiguous. In a follow up discussion it became clear that there are two essential usecases here. One is to use memory.reclaim to pro-actively reclaim memory and expectation is that the requested and reported amount of memory is uncharged from the memcg. Another usecase focuses on pro-active demotion when the memory is merely shuffled around to demotion targets while the overall charged memory stays unchanged. The current implementation considers demoted pages as reclaimed and that break both usecases. [1] has tried to address the reporting part but there are more issues with that summarized in [2] and follow up emails. Let's revert the nodemask based extension of the memcg pro-active reclaim for now until we settle with a more robust semantic. [1] http://lkml.kernel.org/r/http://lkml.kernel.org/r/20221206023406.3182800-1-almasrymina@google.com [2] http://lkml.kernel.org/r/Y5bsmpCyeryu3Zz1@dhcp22.suse.cz Link: https://lkml.kernel.org/r/Y5xASNe1x8cusiTx@dhcp22.suse.cz Fixes: 12a5d3955227b0d ("mm: add nodes= arg to memory.reclaim") Signed-off-by: Michal Hocko Cc: Bagas Sanjaya Cc: Huang Ying Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Mina Almasry Cc: Muchun Song Cc: Roman Gushchin Cc: Shakeel Butt Cc: Tejun Heo Cc: Wei Xu Cc: Yang Shi Cc: Yosry Ahmed Cc: zefan li Signed-off-by: Andrew Morton --- mm/memcontrol.c | 67 +++++++++++---------------------------------------------- 1 file changed, 13 insertions(+), 54 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ab457f0394ab..73afff8062f9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -63,7 +63,6 @@ #include #include #include -#include #include "internal.h" #include #include @@ -2393,8 +2392,7 @@ static unsigned long reclaim_high(struct mem_cgroup *memcg, psi_memstall_enter(&pflags); nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, - MEMCG_RECLAIM_MAY_SWAP, - NULL); + MEMCG_RECLAIM_MAY_SWAP); psi_memstall_leave(&pflags); } while ((memcg = parent_mem_cgroup(memcg)) && !mem_cgroup_is_root(memcg)); @@ -2685,8 +2683,7 @@ retry: psi_memstall_enter(&pflags); nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, - gfp_mask, reclaim_options, - NULL); + gfp_mask, reclaim_options); psi_memstall_leave(&pflags); if (mem_cgroup_margin(mem_over_limit) >= nr_pages) @@ -3506,8 +3503,7 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg, } if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, - memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP, - NULL)) { + memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP)) { ret = -EBUSY; break; } @@ -3618,8 +3614,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) return -EINTR; if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, - MEMCG_RECLAIM_MAY_SWAP, - NULL)) + MEMCG_RECLAIM_MAY_SWAP)) nr_retries--; } @@ -6429,8 +6424,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, } reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, - GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, - NULL); + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP); if (!reclaimed && !nr_retries--) break; @@ -6479,8 +6473,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, if (nr_reclaims) { if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, - GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, - NULL)) + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP)) nr_reclaims--; continue; } @@ -6603,54 +6596,21 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of, return nbytes; } -enum { - MEMORY_RECLAIM_NODES = 0, - MEMORY_RECLAIM_NULL, -}; - -static const match_table_t if_tokens = { - { MEMORY_RECLAIM_NODES, "nodes=%s" }, - { MEMORY_RECLAIM_NULL, NULL }, -}; - static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); unsigned int nr_retries = MAX_RECLAIM_RETRIES; unsigned long nr_to_reclaim, nr_reclaimed = 0; - unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP | - MEMCG_RECLAIM_PROACTIVE; - char *old_buf, *start; - substring_t args[MAX_OPT_ARGS]; - int token; - char value[256]; - nodemask_t nodemask = NODE_MASK_ALL; - - buf = strstrip(buf); - - old_buf = buf; - nr_to_reclaim = memparse(buf, &buf) / PAGE_SIZE; - if (buf == old_buf) - return -EINVAL; + unsigned int reclaim_options; + int err; buf = strstrip(buf); + err = page_counter_memparse(buf, "", &nr_to_reclaim); + if (err) + return err; - while ((start = strsep(&buf, " ")) != NULL) { - if (!strlen(start)) - continue; - token = match_token(start, if_tokens, args); - match_strlcpy(value, args, sizeof(value)); - switch (token) { - case MEMORY_RECLAIM_NODES: - if (nodelist_parse(value, nodemask) < 0) - return -EINVAL; - break; - default: - return -EINVAL; - } - } - + reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE; while (nr_reclaimed < nr_to_reclaim) { unsigned long reclaimed; @@ -6667,8 +6627,7 @@ static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_to_reclaim - nr_reclaimed, - GFP_KERNEL, reclaim_options, - &nodemask); + GFP_KERNEL, reclaim_options); if (!reclaimed && !nr_retries--) return -EAGAIN; -- cgit v1.2.3-70-g09d2