RH30: Virtual Mem shot heavily by locale-archive...

From: Arijit Das (Arijit.Das_at_synopsys.com)
Date: 09/30/05

  • Next message: Dave Jones: "Re: em64t speedstep technology not supported in kernel yet?" 
    Date:	Fri, 30 Sep 2005 18:31:44 +0530
To: <linux-kernel@vger.kernel.org>

    I have RH3.0 installed in an AMD64 machine.
     
    In this system, when I look at the virtual address space mappings of a process (say a sleep process), I find that almost 80% of its virtual address space has been taken by a private copy of /usr/lib/locale/locale-archive mapped to its virtual address space by default. Check this:
     
         31396 KB    r--p    /usr/lib/locale/locale-archive
     
    Total Virtual Memory = 38816 KB
    On the other hand, when I look at the same info in a RH7.2 system, I see that a few small set of essential locale files have been mapped whose overall summed up size is around 236KB (way smaller than RH3.0)...Check this:
             4    r--p    /usr/lib/locale/en_US/LC_IDENTIFICATION
             4    r--p    /usr/lib/locale/en_US/LC_MEASUREMENT
             4    r--p    /usr/lib/locale/en_US/LC_TELEPHONE
             4    r--p    /usr/lib/locale/en_US/LC_ADDRESS
             4    r--p    /usr/lib/locale/en_US/LC_NAME
             4    r--p    /usr/lib/locale/en_US/LC_PAPER
             4    r--p    /usr/lib/locale/en_US/LC_MESSAGES/SYS_LC_MESSAGES
             4    r--p    /usr/lib/locale/en_US/LC_MONETARY
            24    r--p    /usr/lib/locale/en_US/LC_COLLATE
             4    r--p    /usr/lib/locale/en_US/LC_TIME
             4    r--p    /usr/lib/locale/en_US/LC_NUMERIC
           172    r--p    /usr/lib/locale/en_US/LC_CTYPE
    This seems like a huge requirement of memory for each small process executed in the RH3.0 system and hence, shots up the memory requirement of the entire system because the mapped region /usr/lib/locale/locale-archive is privately mapped.
     
    Question: 
     1) Is there any way by which I can instruct my RH3.0 system not to map the huge locale-archive file by default? Rather it should map the few small set of locale files, as mapped in RH7.2 system.
     2) If the answer of my previous question is yes (it is possible), then what will be the impact of doing that?
     
    You can find the sample "sleep" commands below.
     
    Thanks,
    Arijit
     
    RH3.0 on AMD64:
    =============
    vgamd126:arijit>sleep 400 &                                                                                    
    [1] 19916
    vgamd126:arijit>pmap 19916
     Size (KB)    Perm    Associated files (if any)                   
    ==========    ====    =============================================
            16    r-xp    /bin/sleep
             4    rw-p    /bin/sleep
           132    rwxp   
          1108    r-xp    /lib64/ld-2.3.2.so
             4    rw-p    /lib64/ld-2.3.2.so
             4    rw-p   
           540    r-xp    /lib64/tls/libm-2.3.2.so
          1024    ---p    /lib64/tls/libm-2.3.2.so
             4    rw-p    /lib64/tls/libm-2.3.2.so
             4    rw-p   
            36    r-xp    /lib64/tls/librtkaio-2.3.2.so
          1024    ---p    /lib64/tls/librtkaio-2.3.2.so
             4    rw-p    /lib64/tls/librtkaio-2.3.2.so
            64    rw-p   
          1260    r-xp    /lib64/tls/libc-2.3.2.so
          1024    ---p    /lib64/tls/libc-2.3.2.so
            20    rw-p    /lib64/tls/libc-2.3.2.so
            16    rw-p   
            60    r-xp    /lib64/tls/libpthread-0.60.so
          1024    ---p    /lib64/tls/libpthread-0.60.so
             4    rw-p    /lib64/tls/libpthread-0.60.so
            20    rw-p   
         31396    r--p    /usr/lib/locale/locale-archive
            24    rw-p   
    Total Virtual Memory = 38816 KB
    vgamd126:arijit>
     
     
    RH7.2 in i686
    ==========
    eurika120:arijit>sleep 400 &                                                                                           
    [1] 11065
    eurika120:arijit>pmap 11065
     Size (KB)    Perm    Associated files (if any)                   
    ==========    ====    =============================================
            12    r-xp    /bin/sleep
             4    rw-p    /bin/sleep
             8    rwxp   
            88    r-xp    /lib/ld-2.2.4.so
             4    rw-p    /lib/ld-2.2.4.so
             4    r--p    /usr/lib/locale/en_US/LC_IDENTIFICATION
             4    r--p    /usr/lib/locale/en_US/LC_MEASUREMENT
             4    r--p    /usr/lib/locale/en_US/LC_TELEPHONE
             4    r--p    /usr/lib/locale/en_US/LC_ADDRESS
             4    r--p    /usr/lib/locale/en_US/LC_NAME
             4    r--p    /usr/lib/locale/en_US/LC_PAPER
             4    r--p    /usr/lib/locale/en_US/LC_MESSAGES/SYS_LC_MESSAGES
             4    r--p    /usr/lib/locale/en_US/LC_MONETARY
            24    r--p    /usr/lib/locale/en_US/LC_COLLATE
             4    r--p    /usr/lib/locale/en_US/LC_TIME
             4    r--p    /usr/lib/locale/en_US/LC_NUMERIC
             4    rw-p   
           136    r-xp    /lib/i686/libm-2.2.4.so
             4    rw-p    /lib/i686/libm-2.2.4.so
            28    r-xp    /lib/librt-2.2.4.so
             4    rw-p    /lib/librt-2.2.4.so
            40    rw-p   
          1224    r-xp    /lib/i686/libc-2.2.4.so
            20    rw-p    /lib/i686/libc-2.2.4.so
            16    rw-p   
            52    r-xp    /lib/i686/libpthread-0.9.so
            32    rw-p    /lib/i686/libpthread-0.9.so
           172    r--p    /usr/lib/locale/en_US/LC_CTYPE
            24    rwxp   
    Total Virtual Memory = 1936 KB
    eurika120:arijit>

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  • Next message: Dave Jones: "Re: em64t speedstep technology not supported in kernel yet?"