• Minchan Kim's avatar
    zram: report maximum used memory · 461a8eee
    Minchan Kim authored
    Normally, zram user could get maximum memory usage zram consumed via
    polling mem_used_total with sysfs in userspace.
    
    But it has a critical problem because user can miss peak memory usage
    during update inverval of polling.  For avoiding that, user should poll it
    with shorter interval(ie, 0.0000000001s) with mlocking to avoid page fault
    delay when memory pressure is heavy.  It would be troublesome.
    
    This patch adds new knob "mem_used_max" so user could see the maximum
    memory usage easily via reading the knob and reset it via "echo 0 >
    /sys/block/zram0/mem_used_max".
    Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
    Reviewed-by: default avatarDan Streetman <ddstreet@ieee.org>
    Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
    Cc: Jerome Marchand <jmarchan@redhat.com>
    Cc: <juno.choi@lge.com>
    Cc: <seungho1.park@lge.com>
    Cc: Luigi Semenzato <semenzato@google.com>
    Cc: Nitin Gupta <ngupta@vflare.org>
    Cc: Seth Jennings <sjennings@variantweb.net>
    Reviewed-by: default avatarDavid Horner <ds2horner@gmail.com>
    Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    461a8eee
zram_drv.c 27.3 KB