[RFC PATCH] meminfo: Break apart a very long seq_printf with #ifdefs

From: Joe Perches
Date: Wed Aug 10 2016 - 14:24:53 EST


Use a specific routine to emit most lines so that the code is
easier to read and maintain.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---

compiled but untested

fs/proc/meminfo.c | 211 ++++++++++++++++++++++++------------------------------
1 file changed, 95 insertions(+), 116 deletions(-)

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 09e18fd..c5073b8 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -23,6 +23,25 @@ void __attribute__((weak)) arch_report_meminfo(struct seq_file *m)
{
}

+static void show_val_kb(struct seq_file *m, const char *s, unsigned long num)
+{
+ char v[32];
+ static const char blanks[7] = {' ', ' ', ' ', ' ',' ', ' ', ' '};
+ int len;
+
+ len = num_to_str(v, sizeof(v), num << (PAGE_SHIFT - 10));
+
+ seq_write(m, s, 16);
+
+ if (len > 0) {
+ if (len < 8)
+ seq_write(m, blanks, 8 - len);
+
+ seq_write(m, v, len);
+ }
+ seq_write(m, " kB\n", 4);
+}
+
static int meminfo_proc_show(struct seq_file *m, void *v)
{
struct sysinfo i;
@@ -32,10 +51,6 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
unsigned long pages[NR_LRU_LISTS];
int lru;

-/*
- * display in kilobytes.
- */
-#define K(x) ((x) << (PAGE_SHIFT - 10))
si_meminfo(&i);
si_swapinfo(&i);
committed = percpu_counter_read_positive(&vm_committed_as);
@@ -50,136 +65,100 @@ static int meminfo_proc_show(struct seq_file *m, void *v)

available = si_mem_available();

- /*
- * Tagged format, for easy grepping and expansion.
- */
- seq_printf(m,
- "MemTotal: %8lu kB\n"
- "MemFree: %8lu kB\n"
- "MemAvailable: %8lu kB\n"
- "Buffers: %8lu kB\n"
- "Cached: %8lu kB\n"
- "SwapCached: %8lu kB\n"
- "Active: %8lu kB\n"
- "Inactive: %8lu kB\n"
- "Active(anon): %8lu kB\n"
- "Inactive(anon): %8lu kB\n"
- "Active(file): %8lu kB\n"
- "Inactive(file): %8lu kB\n"
- "Unevictable: %8lu kB\n"
- "Mlocked: %8lu kB\n"
-#ifdef CONFIG_HIGHMEM
- "HighTotal: %8lu kB\n"
- "HighFree: %8lu kB\n"
- "LowTotal: %8lu kB\n"
- "LowFree: %8lu kB\n"
-#endif
-#ifndef CONFIG_MMU
- "MmapCopy: %8lu kB\n"
-#endif
- "SwapTotal: %8lu kB\n"
- "SwapFree: %8lu kB\n"
- "Dirty: %8lu kB\n"
- "Writeback: %8lu kB\n"
- "AnonPages: %8lu kB\n"
- "Mapped: %8lu kB\n"
- "Shmem: %8lu kB\n"
- "Slab: %8lu kB\n"
- "SReclaimable: %8lu kB\n"
- "SUnreclaim: %8lu kB\n"
- "KernelStack: %8lu kB\n"
- "PageTables: %8lu kB\n"
-#ifdef CONFIG_QUICKLIST
- "Quicklists: %8lu kB\n"
-#endif
- "NFS_Unstable: %8lu kB\n"
- "Bounce: %8lu kB\n"
- "WritebackTmp: %8lu kB\n"
- "CommitLimit: %8lu kB\n"
- "Committed_AS: %8lu kB\n"
- "VmallocTotal: %8lu kB\n"
- "VmallocUsed: %8lu kB\n"
- "VmallocChunk: %8lu kB\n"
-#ifdef CONFIG_MEMORY_FAILURE
- "HardwareCorrupted: %5lu kB\n"
-#endif
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- "AnonHugePages: %8lu kB\n"
- "ShmemHugePages: %8lu kB\n"
- "ShmemPmdMapped: %8lu kB\n"
-#endif
-#ifdef CONFIG_CMA
- "CmaTotal: %8lu kB\n"
- "CmaFree: %8lu kB\n"
-#endif
- ,
- K(i.totalram),
- K(i.freeram),
- K(available),
- K(i.bufferram),
- K(cached),
- K(total_swapcache_pages()),
- K(pages[LRU_ACTIVE_ANON] + pages[LRU_ACTIVE_FILE]),
- K(pages[LRU_INACTIVE_ANON] + pages[LRU_INACTIVE_FILE]),
- K(pages[LRU_ACTIVE_ANON]),
- K(pages[LRU_INACTIVE_ANON]),
- K(pages[LRU_ACTIVE_FILE]),
- K(pages[LRU_INACTIVE_FILE]),
- K(pages[LRU_UNEVICTABLE]),
- K(global_page_state(NR_MLOCK)),
+ show_val_kb(m, "MemTotal: ", i.totalram);
+ show_val_kb(m, "MemFree: ", i.freeram);
+ show_val_kb(m, "MemAvailable: ", available);
+ show_val_kb(m, "Buffers: ", i.bufferram);
+ show_val_kb(m, "Cached: ", cached);
+ show_val_kb(m, "SwapCached: ", total_swapcache_pages());
+ show_val_kb(m, "Active: ", pages[LRU_ACTIVE_ANON] +
+ pages[LRU_ACTIVE_FILE]);
+ show_val_kb(m, "Inactive: ", pages[LRU_INACTIVE_ANON] +
+ pages[LRU_INACTIVE_FILE]);
+ show_val_kb(m, "Active(anon): ", pages[LRU_ACTIVE_ANON]);
+ show_val_kb(m, "Inactive(anon): ", pages[LRU_INACTIVE_ANON]);
+ show_val_kb(m, "Active(file): ", pages[LRU_ACTIVE_FILE]);
+ show_val_kb(m, "Inactive(file): ", pages[LRU_INACTIVE_FILE]);
+ show_val_kb(m, "Unevictable: ", pages[LRU_UNEVICTABLE]);
+ show_val_kb(m, "Mlocked: ", global_page_state(NR_MLOCK));
+
#ifdef CONFIG_HIGHMEM
- K(i.totalhigh),
- K(i.freehigh),
- K(i.totalram-i.totalhigh),
- K(i.freeram-i.freehigh),
+ show_val_kb(m, "HighTotal: ", i.totalhigh);
+ show_val_kb(m, "HighFree: ", i.freehigh);
+ show_val_kb(m, "LowTotal: ", i.totalram - i.totalhigh);
+ show_val_kb(m, "LowFree: ", i.freeram - i.freehigh);
#endif
+
#ifndef CONFIG_MMU
- K((unsigned long) atomic_long_read(&mmap_pages_allocated)),
+ show_val_kb(m, "MmapCopy: ",
+ (unsigned long)atomic_long_read(&mmap_pages_allocated));
#endif
- K(i.totalswap),
- K(i.freeswap),
- K(global_node_page_state(NR_FILE_DIRTY)),
- K(global_node_page_state(NR_WRITEBACK)),
- K(global_node_page_state(NR_ANON_MAPPED)),
- K(global_node_page_state(NR_FILE_MAPPED)),
- K(i.sharedram),
- K(global_page_state(NR_SLAB_RECLAIMABLE) +
- global_page_state(NR_SLAB_UNRECLAIMABLE)),
- K(global_page_state(NR_SLAB_RECLAIMABLE)),
- K(global_page_state(NR_SLAB_UNRECLAIMABLE)),
- global_page_state(NR_KERNEL_STACK_KB),
- K(global_page_state(NR_PAGETABLE)),
+
+ show_val_kb(m, "SwapTotal: ", i.totalswap);
+ show_val_kb(m, "SwapFree: ", i.freeswap);
+ show_val_kb(m, "Dirty: ",
+ global_node_page_state(NR_FILE_DIRTY));
+ show_val_kb(m, "Writeback: ",
+ global_node_page_state(NR_WRITEBACK));
+ show_val_kb(m, "AnonPages: ",
+ global_node_page_state(NR_ANON_MAPPED));
+ show_val_kb(m, "Mapped: ",
+ global_node_page_state(NR_FILE_MAPPED));
+ show_val_kb(m, "Shmem: ", i.sharedram);
+ show_val_kb(m, "Slab: ",
+ global_page_state(NR_SLAB_RECLAIMABLE) +
+ global_page_state(NR_SLAB_UNRECLAIMABLE));
+
+ show_val_kb(m, "SReclaimable: ",
+ global_page_state(NR_SLAB_RECLAIMABLE));
+ show_val_kb(m, "SUnreclaim: ",
+ global_page_state(NR_SLAB_UNRECLAIMABLE));
+ seq_printf(m, "KernelStack: %8lu kB\n",
+ global_page_state(NR_KERNEL_STACK_KB));
+ show_val_kb(m, "PageTables: ",
+ global_page_state(NR_PAGETABLE));
#ifdef CONFIG_QUICKLIST
- K(quicklist_total_size()),
+ show_val_kb(m, "Quicklists: ", quicklist_total_size());
#endif
- K(global_node_page_state(NR_UNSTABLE_NFS)),
- K(global_page_state(NR_BOUNCE)),
- K(global_node_page_state(NR_WRITEBACK_TEMP)),
- K(vm_commit_limit()),
- K(committed),
- (unsigned long)VMALLOC_TOTAL >> 10,
- 0ul, // used to be vmalloc 'used'
- 0ul // used to be vmalloc 'largest_chunk'
+
+ show_val_kb(m, "NFS_Unstable: ",
+ global_node_page_state(NR_UNSTABLE_NFS));
+ show_val_kb(m, "Bounce: ",
+ global_page_state(NR_BOUNCE));
+ show_val_kb(m, "WritebackTmp: ",
+ global_node_page_state(NR_WRITEBACK_TEMP));
+ show_val_kb(m, "CommitLimit: ", vm_commit_limit());
+ show_val_kb(m, "Committed_AS: ", committed);
+ seq_printf(m, "VmallocTotal: %8lu kB\n",
+ (unsigned long)VMALLOC_TOTAL >> 10);
+ show_val_kb(m, "VmallocUsed: ", 0ul);
+ show_val_kb(m, "VmallocChunk: ", 0ul);
+
#ifdef CONFIG_MEMORY_FAILURE
- , atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
+ seq_printf(m, "HardwareCorrupted: %5lu kB\n",
+ atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10));
#endif
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- , K(global_node_page_state(NR_ANON_THPS) * HPAGE_PMD_NR)
- , K(global_node_page_state(NR_SHMEM_THPS) * HPAGE_PMD_NR)
- , K(global_node_page_state(NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR)
+ show_val_kb(m, "AnonHugePages: ",
+ global_node_page_state(NR_ANON_THPS) * HPAGE_PMD_NR);
+ show_val_kb(m, "ShmemHugePages: ",
+ global_node_page_state(NR_SHMEM_THPS) * HPAGE_PMD_NR);
+ show_val_kb(m, "ShmemPmdMapped: ",
+ global_node_page_state(NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR);
#endif
+
#ifdef CONFIG_CMA
- , K(totalcma_pages)
- , K(global_page_state(NR_FREE_CMA_PAGES))
+ show_val_kb(m, "CmaTotal: ", totalcma_pages);
+ show_val_kb(m, "CmaFree: ",
+ global_page_state(NR_FREE_CMA_PAGES));
#endif
- );

hugetlb_report_meminfo(m);

arch_report_meminfo(m);

return 0;
-#undef K
}

static int meminfo_proc_open(struct inode *inode, struct file *file)
--
2.8.0.rc4.16.g56331f8