Re: [PATCHv3 09/13] scripts/gdb: Add meminfo command

[Kieran Bingham]

On 13/03/16 16:34, Jan Kiszka wrote:
> On 2016-03-03 12:41, Kieran Bingham wrote:
>> Provide an equivalent of /proc/meminfo which should be available from
>> core dumps, or crashed kernels. This should allow a debugger to identify
>> if memory pressures were applicable in the instance of their issue
>>
> 
> Sound useful.
> 
>> Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxx>
>>
>> ---
>>
>> Changes from v1:
>>  - Updated to use LX_ macros for constants
>>  - Utilise the LX_CONFIG() options for conditional printing
>>  - Fixed meminfo command on Jan's target .config
>>  - Added missing segments to meminfo command (HUGEPAGE, QUICKLIST)
>>  - Adjusted for new list_for_each_entry() function
>>  - Fixed up for !CONFIG_SWAP and !CONFIG_MMU targets (Tested STM32)
>>
>> Changes from v2:
>>  - Reduce line size on output lines causing pep8 warnings
>>  - Remove crept in 'pass' statement
>> ---
>>  scripts/gdb/linux/constants.py.in |  34 ++++++
>>  scripts/gdb/linux/proc.py         | 228 ++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 262 insertions(+)
>>
>> diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
>> index 57213ad8cf75..66562a8242bd 100644
>> --- a/scripts/gdb/linux/constants.py.in
>> +++ b/scripts/gdb/linux/constants.py.in
>> @@ -12,8 +12,16 @@
>>   *
>>   */
>>  
>> +#include <asm/page.h>
>> +#include <asm/pgtable.h>
>> +#include <asm/thread_info.h>
>> +
>>  #include <linux/fs.h>
>> +#include <linux/swap.h>
>>  #include <linux/mount.h>
>> +#include <linux/huge_mm.h>
>> +#include <linux/vmalloc.h>
>> +
>>  
>>  /* We need to stringify expanded macros so that they can be parsed */
>>  
>> @@ -51,3 +59,29 @@ LX_VALUE(MNT_NOATIME)
>>  LX_VALUE(MNT_NODIRATIME)
>>  LX_VALUE(MNT_RELATIME)
>>  
>> +/* asm/page.h */
>> +LX_GDBPARSED(PAGE_SHIFT)
>> +
>> +/* asm/thread_info.h */
>> +LX_GDBPARSED(THREAD_SIZE)
>> +
>> +/* linux/vmalloc.h */
>> +LX_GDBPARSED(VMALLOC_TOTAL)
>> +
>> +/* linux/swap.h */
>> +LX_GDBPARSED(MAX_SWAPFILES)
>> +
>> +
>> +/* Kernel Configs */
>> +LX_CONFIG(CONFIG_HIGHMEM)
>> +LX_CONFIG(CONFIG_MEMORY_FAILURE)
>> +LX_CONFIG(CONFIG_TRANSPARENT_HUGEPAGE)
>> +LX_CONFIG(CONFIG_CMA)
>> +LX_CONFIG(CONFIG_MMU)
>> +LX_CONFIG(CONFIG_SWAP)
>> +
>> +#ifndef CONFIG_NR_QUICK
>> +#define CONFIG_NR_QUICK 0
>> +#endif
>> +LX_VALUE(CONFIG_NR_QUICK)
>> +LX_CONFIG(CONFIG_QUICKLIST)
>> diff --git a/scripts/gdb/linux/proc.py b/scripts/gdb/linux/proc.py
>> index 115f20b07a54..e5a8dbe3aa3a 100644
>> --- a/scripts/gdb/linux/proc.py
>> +++ b/scripts/gdb/linux/proc.py
>> @@ -195,3 +195,231 @@ values of that process namespace"""
>>                          info_opts(MNT_INFO, m_flags)))
>>  
>>  LxMounts()
>> +
>> +
>> +bdev_type = utils.CachedType("struct block_device")
>> +bdev_ptr_type = bdev_type.get_type().pointer()
>> +
>> +
>> +class LxMeminfo(gdb.Command):
>> +    """ Identify the memory usage, statistics, and availability
>> +
>> +Equivalent to cat /proc/meminfo on a running target """
>> +
>> +    def __init__(self):
>> +        super(LxMeminfo, self).__init__("lx-meminfo", gdb.COMMAND_DATA)
>> +
>> +    def K(self, val):
>> +        # Convert from PAGES to KB
>> +        return int(val << (constants.LX_PAGE_SHIFT - 10))
>> +
>> +    def page_K(self, remote_value):
>> +        # Obtain page value, and Convert from PAGES to KB
>> +        val = int(gdb.parse_and_eval(remote_value))
>> +        return self.K(val)
>> +
>> +    def gps(self, enum_zone_stat_item):
>> +        # Access the Global Page State structure
>> +        # I would prefer to read this structure in one go and then index
>> +        # from the enum. But we can't determine the enum values with out
>> +        # a call to GDB anyway so we may as well take the easy route and
>> +        # get the value.
>> +        remote_value = "vm_stat[" + enum_zone_stat_item + "].counter"
>> +        return int(gdb.parse_and_eval(remote_value))
>> +
>> +    def gps_K(self, enum_zone_stat_item):
>> +        return self.K(self.gps(enum_zone_stat_item))
>> +
>> +    def nr_blockdev_pages(self):
>> +        bdevs_head = gdb.parse_and_eval("all_bdevs")
>> +        pages = 0
>> +        for bdev in lists.list_for_each_entry(bdevs_head,
>> +                                              bdev_ptr_type,
>> +                                              "bd_list"):
>> +            try:
>> +                pages += bdev['bd_inode']['i_mapping']['nrpages']
>> +            except:
>> +                # Any memory read failures are simply not counted
>> +                pass
>> +        return pages
>> +
>> +    def total_swapcache_pages(self):
>> +        pages = 0
>> +        if not constants.LX_CONFIG_SWAP:
>> +            return 0
>> +
>> +        for i in range(0, int(constants.LX_MAX_SWAPFILES)):
>> +            swap_space = "swapper_spaces[" + str(i) + "].nrpages"
>> +            pages += int(gdb.parse_and_eval(swap_space))
>> +        return pages
>> +
>> +    def vm_commit_limit(self, totalram_pages):
>> +        total_swap_pages = 0
>> +        overcommit = int(gdb.parse_and_eval("sysctl_overcommit_kbytes"))
>> +        overcommit_ratio = int(gdb.parse_and_eval("sysctl_overcommit_ratio"))
>> +
>> +        if constants.LX_CONFIG_SWAP:
>> +            total_swap_pages = int(gdb.parse_and_eval("total_swap_pages"))
>> +
>> +        hugetlb_total_pages = 0  # hugetlb_total_pages()
>> +
>> +        if overcommit:
>> +            allowed = overcommit >> (constants.LX_PAGE_SHIFT - 10)
>> +        else:
>> +            allowed = ((totalram_pages - hugetlb_total_pages *
>> +                       overcommit_ratio / 100))
>> +
>> +        allowed += total_swap_pages
>> +        return allowed
>> +
>> +    def quicklist_total_size(self):
>> +        count = 0
>> +        quicklist = utils.gdb_eval_or_none("quicklist")
>> +        if quicklist is None:
>> +            return 0
>> +
>> +        for cpu in cpus.each_online_cpu():
>> +            ql = cpus.per_cpu(quicklist, cpu)
>> +            for q in range(0, constants.LX_CONFIG_NR_QUICK):
>> +                # for (q = ql; q < ql + CONFIG_NR_QUICK; q++)
>> +                # count += q->nr_pages
>> +                count += ql[q]['nr_pages']
>> +
>> +        return count
>> +
>> +    # Main lx-meminfo command execution
>> +    # See fs/proc/meminfo.c:meminfo_proc_show()
>> +    def invoke(self, arg, from_tty):
>> +        totalram = int(gdb.parse_and_eval("totalram_pages"))
>> +        freeram = self.gps("NR_FREE_PAGES")
>> +        reclaimable = self.gps("NR_SLAB_RECLAIMABLE")
>> +        unreclaimable = self.gps("NR_SLAB_UNRECLAIMABLE")
>> +        slab = reclaimable + unreclaimable
>> +        # for_each_zone(zone)
>> +        #     wmark_low += zone->watermark[WMARK_LOW];
>> +        wmark_low = 0   # Zone parsing is unimplemented
>> +
>> +        available = freeram - wmark_low
>> +        available += reclaimable - min(reclaimable / 2, wmark_low)
>> +
>> +        bufferram = self.nr_blockdev_pages()
>> +        swapcached = self.total_swapcache_pages()
>> +
>> +        file_pages = self.gps("NR_FILE_PAGES")
>> +        cached = file_pages - swapcached - bufferram
>> +
>> +        # LRU Pages
>> +        active_pages_anon = self.gps("NR_ACTIVE_ANON")
>> +        inactive_pages_anon = self.gps("NR_INACTIVE_ANON")
>> +        active_pages_file = self.gps("NR_ACTIVE_FILE")
>> +        inactive_pages_file = self.gps("NR_INACTIVE_FILE")
>> +        unevictable_pages = self.gps("NR_UNEVICTABLE")
>> +        active_pages = active_pages_anon + active_pages_file
>> +        inactive_pages = inactive_pages_anon + inactive_pages_file
>> +
>> +        kernelstack = int(self.gps("NR_KERNEL_STACK") *
>> +                          constants.LX_THREAD_SIZE / 1024)
>> +
>> +        commitlimit = int(self.vm_commit_limit(totalram))
>> +        committed_as = int(gdb.parse_and_eval("vm_committed_as.count"))
>> +
>> +        vmalloc_total = int(constants.LX_VMALLOC_TOTAL >> 10)
>> +
>> +        gdb.write(
>> +            "MemTotal:       {:8d} kB\n".format(self.K(totalram)) +
>> +            "MemFree:        {:8d} kB\n".format(self.K(freeram)) +
>> +            "MemAvailable:   {:8d} kB\n".format(self.K(available)) +
>> +            "Buffers:        {:8d} kB\n".format(self.K(bufferram)) +
>> +            "Cached:         {:8d} kB\n".format(self.K(cached)) +
>> +            "SwapCached:     {:8d} kB\n".format(self.K(swapcached)) +
>> +            "Active:         {:8d} kB\n".format(self.K(active_pages)) +
>> +            "Inactive:       {:8d} kB\n".format(self.K(inactive_pages)) +
>> +            "Active(anon):   {:8d} kB\n".format(self.K(active_pages_anon)) +
>> +            "Inactive(anon): {:8d} kB\n".format(self.K(inactive_pages_anon)) +
>> +            "Active(file):   {:8d} kB\n".format(self.K(active_pages_file)) +
>> +            "Inactive(file): {:8d} kB\n".format(self.K(inactive_pages_file)) +
>> +            "Unevictable:    {:8d} kB\n".format(self.K(unevictable_pages)) +
>> +            "Mlocked:        {:8d} kB\n".format(self.gps_K("NR_MLOCK"))
>> +            )
>> +
>> +        if constants.LX_CONFIG_HIGHMEM:
>> +            totalhigh = int(gdb.parse_and_eval("totalhigh_pages"))
>> +            freehigh = int(gdb.parse_and_eval("nr_free_highpages()"))
>> +            lowtotal = totalram - totalhigh
>> +            lowfree = freeram - freehigh
>> +            gdb.write(
>> +                "HighTotal:      {:8d} kB\n".format(self.K(totalhigh)) +
>> +                "HighFree:       {:8d} kB\n".format(self.K(freehigh)) +
>> +                "LowTotal:       {:8d} kB\n".format(self.K(lowtotal)) +
>> +                "LowFree:        {:8d} kB\n".format(self.K(lowfree))
>> +                )
>> +
>> +        if not constants.LX_CONFIG_MMU:
>> +            mmap_pg_alloc = gdb.parse_and_eval("mmap_pages_allocated.counter")
>> +            gdb.write(
>> +                "MmapCopy:       {:8d} kB\n".format(self.K(mmap_pg_alloc))
>> +                )
>> +
>> +        gdb.write(
>> +            "SwapTotal:      {:8d} kB\n".format(self.K(0)) +
>> +            "SwapFree:       {:8d} kB\n".format(self.K(0)) +
>> +            "Dirty:          {:8d} kB\n".format(self.gps_K("NR_FILE_DIRTY")) +
>> +            "Writeback:      {:8d} kB\n".format(self.gps_K("NR_WRITEBACK")) +
>> +            "AnonPages:      {:8d} kB\n".format(self.gps_K("NR_ANON_PAGES")) +
>> +            "Mapped:         {:8d} kB\n".format(self.gps_K("NR_FILE_MAPPED")) +
>> +            "Shmem:          {:8d} kB\n".format(self.gps_K("NR_SHMEM")) +
>> +            "Slab:           {:8d} kB\n".format(self.K(slab)) +
>> +            "SReclaimable:   {:8d} kB\n".format(self.K(reclaimable)) +
>> +            "SUnreclaim:     {:8d} kB\n".format(self.K(unreclaimable)) +
>> +            "KernelStack:    {:8d} kB\n".format(kernelstack) +
>> +            "PageTables:     {:8d} kB\n".format(self.gps_K("NR_PAGETABLE"))
>> +            )
>> +
>> +        if constants.LX_CONFIG_QUICKLIST:
>> +            quicklist = self.quicklist_total_size()
>> +            gdb.write(
>> +               "Quicklists:     {:8d} kB\n".format(self.K(quicklist))
> 
> scripts/gdb/linux/proc.py:381:16: E121 continuation line under-indented
> for hanging indent
> 
> Please make sure to run pep8 on the series before posting.

My apologies for the error, but on my laptop pep8 runs clean?

What version are you running?
I have the following:

$ pep8 --version
1.6.2

Perhaps I need to update something here.

Kieran