This patch series allows setting all zswap params at runtime, instead of only being settable at boot-time. The changes to zswap are rather large, due to the creation of zswap pools, which contain both a compressor function as well as a zpool. When either the compressor or zpool param is changed at runtime, a new zswap pool is created with the new compressor and zpool, and used for all new compressed pages. Any old zswap pools that still contain pages are retained only to load pages from, and destroyed once they become empty. One notable change required for this to work is to split the currently global kernel param mutex into a global mutex only for built-in params, and a per-module mutex for loadable module params. The reason this change is required is because zswap's compressor and zpool param handler callback functions attempt to load, via crypto_has_comp() and the new zpool_has_pool() functions, any required compressor or zpool modules. The problem there is that the zswap param callback functions run while the global param mutex is locked, but when they attempt to load another module, if the loading module has any params set e.g. via /etc/modprobe.d/*.conf, modprobe will also try to take the global param mutex, and a deadlock will result, with the mutex held by the zswap param callback which is waiting for modprobe, but modprobe waiting for the mutex to change the loading module's param. Using a per-module mutex for all loadable modules prevents this, since each module will take its own mutex and never conflict with another module's param changes. Dan Streetman (5): zpool: add zpool_has_pool() module: add per-module params lock zswap: runtime enable/disable zswap: dynamic pool creation zswap: change zpool/compressor at runtime arch/um/drivers/hostaudio_kern.c | 20 +- drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 6 +- drivers/net/wireless/libertas_tf/if_usb.c | 6 +- drivers/usb/atm/ueagle-atm.c | 4 +- drivers/video/fbdev/vt8623fb.c | 4 +- include/linux/module.h | 1 + include/linux/moduleparam.h | 67 +-- include/linux/zpool.h | 2 + kernel/module.c | 1 + kernel/params.c | 45 +- mm/zpool.c | 25 + mm/zswap.c | 696 +++++++++++++++++------ net/mac80211/rate.c | 4 +- 13 files changed, 640 insertions(+), 241 deletions(-) -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>