Re: [PATCH 2/4] writeback: allow for dirty metadata accounting
From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2016-09-22 19:48:29
Also in:
linux-fsdevel, linux-mm
Hi Josef, as we talked off line, I think the idea of maintaining a byte counter and rounding in balance_dirty_pages() is the best way to do this. And Jan spotted all the actual bugs, so I only have a few nitpicks :) On Tue, Sep 20, 2016 at 04:57:46PM -0400, Josef Bacik wrote:
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@@ -44,12 +44,13 @@ void show_mem(unsigned int filter) { struct zone *zone; - pr_err("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu free:%lu\n slab:%lu mapped:%lu pagetables:%lu bounce:%lu pagecache:%lu swap:%lu\n", + pr_err("Active:%lu inactive:%lu dirty:%lu metadata_dirty:%lu writeback:%lu unstable:%lu free:%lu\n slab:%lu mapped:%lu pagetables:%lu bounce:%lu pagecache:%lu swap:%lu\n", (global_node_page_state(NR_ACTIVE_ANON) + global_node_page_state(NR_ACTIVE_FILE)), (global_node_page_state(NR_INACTIVE_ANON) + global_node_page_state(NR_INACTIVE_FILE)), global_node_page_state(NR_FILE_DIRTY), + global_node_page_state(NR_METADATA_DIRTY), global_node_page_state(NR_WRITEBACK),
Print NR_METADATA_WRITEBACK here as well?
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@@ -51,6 +51,8 @@ static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL); #define K(x) ((x) << (PAGE_SHIFT - 10)) +#define BtoK(x) ((x) >> 10) + static ssize_t node_read_meminfo(struct device *dev, struct device_attribute *attr, char *buf) {@@ -99,7 +101,9 @@ static ssize_t node_read_meminfo(struct device *dev, #endif n += sprintf(buf + n, "Node %d Dirty: %8lu kB\n" + "Node %d MetadataDirty: %8lu kB\n" "Node %d Writeback: %8lu kB\n" + "Node %d MetaWriteback: %8lu kB\n"
Between the enums and stat printing, the naming is kind of all over the place. How about NR_META_DIRTY_BYTES and NR_META_WRITEBACK_BYTES as a separate group than the existing dirty & writeback stats? n += sprintf(buf + n, "Node %d Dirty: %8lu kB\n" "Node %d Writeback: %8lu kB\n" + "Node %d MetaDirty: %8lu kB\n" + "Node %d MetaWriteback: %8lu kB\n"
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"Node %d FilePages: %8lu kB\n" "Node %d Mapped: %8lu kB\n" "Node %d AnonPages: %8lu kB\n"@@ -119,7 +123,9 @@ static ssize_t node_read_meminfo(struct device *dev, #endif , nid, K(node_page_state(pgdat, NR_FILE_DIRTY)), + nid, BtoK(node_page_state(pgdat, NR_METADATA_DIRTY_BYTES)), nid, K(node_page_state(pgdat, NR_WRITEBACK)), + nid, BtoK(node_page_state(pgdat, NR_METADATA_WRITEBACK_BYTES)), nid, K(node_page_state(pgdat, NR_FILE_PAGES)), nid, K(node_page_state(pgdat, NR_FILE_MAPPED)), nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 56c8fda..aafdb11 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c@@ -1801,6 +1801,7 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb) return work; } +#define BtoP(x) ((x) >> PAGE_SHIFT)
Might be more readable inline:
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@@ -1809,6 +1810,7 @@ static unsigned long get_nr_dirty_pages(void) { return global_node_page_state(NR_FILE_DIRTY) + global_node_page_state(NR_UNSTABLE_NFS) + + BtoP(global_node_page_state(NR_METADATA_DIRTY_BYTES)) +
global_node_page_state(NR_META_DIRTY_BYTES) / PAGE_SIZE +
get_nr_dirty_inodes(); }
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@@ -80,7 +81,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v) "SwapTotal: %8lu kB\n" "SwapFree: %8lu kB\n" "Dirty: %8lu kB\n" + "MetadataDirty: %8lu kB\n" "Writeback: %8lu kB\n" + "MetaWriteback: %8lu kB\n"
"Dirty: %8lu kB\n" "Writeback: %8lu kB\n" + "MetaDirty: %8lu kB\n" + "MetaWriteback: %8lu kB\n"
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"AnonPages: %8lu kB\n" "Mapped: %8lu kB\n" "Shmem: %8lu kB\n"@@ -139,7 +142,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v) K(i.totalswap), K(i.freeswap), K(global_node_page_state(NR_FILE_DIRTY)), + BtoK(global_node_page_state(NR_METADATA_DIRTY_BYTES)), K(global_node_page_state(NR_WRITEBACK)), + BtoK(global_node_page_state(NR_META_WRITEBACK_BYTES)),
K(global_node_page_state(NR_META_WRITEBACK_BYTES / PAGE_SIZE)), and drop BtoK?
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@@ -34,6 +34,8 @@ typedef int (congested_fn)(void *, int); enum wb_stat_item { WB_RECLAIMABLE, WB_WRITEBACK, + WB_METADATA_DIRTY_BYTES, + WB_METADATA_WRITEBACK_BYTES,
WB_META_DIRTY_BYTES, WB_META_WRITEBACK_BYTES, etc.