Lines Matching full:backend

48 If a backend chooses, frontswap can be configured as a "writethrough
51 in order to allow the backend to arbitrarily "reclaim" space used to
75 A backend implementation may provide additional metrics.
121 Specifically, the Xen Transcendent Memory backend allows otherwise
140 swap device.  If CONFIG_FRONTSWAP is enabled but no frontswap "backend"
143 AND a frontswap backend registers AND the backend fails every "store"
150 As for space, if CONFIG_FRONTSWAP is enabled AND a frontswap backend
163 backend, such as zcache, must implement policies to carefully (but
169 Let's assume that a frontswap "backend" has registered during
171 frontswap backend has access to some "memory" that is not directly
182 consults with the frontswap backend and if the backend says it does NOT
185 backend is unpredictable to the kernel; it may choose to never accept a
187 page.  But if the backend does accept a page, the data from the page
189 and the backend guarantees the persistence of the data.  In this case,
196 see if the page was earlier accepted by the frontswap backend.  If
197 it was, the page of data is filled from the frontswap backend and
201 So every time the frontswap backend accepts a page, a swap device read
202 and (potentially) a swap device write are replaced by a "frontswap backend
203 store" and (possibly) a "frontswap backend loads", which are presumably much
219 For example, the acceptance of any swap page by the frontswap backend is
222 backend.  In zcache, one cannot know a priori how compressible a page is.
231 required to ensure the dynamicity of the backend and to avoid thorny race
255 can still use frontswap but a backend for such devices must configure
265 is non-compressible and so would take the entire 4K.  But the backend