On Sun, Mar 10, 2019 at 07:17:08PM +0300, Alexey Budankov wrote: SNIP
> > so to be on the same page.. normal processing without compression is: > > > > perf_mmap__push does: > > push(mmap buf) > > record__pushfn > > record__write > > write(buf) > > > > perf_mmap__aio_push does: > > memcpy(aio buf, mmap buf) > > push(aio buf) > > record__aio_pushfn > > record__aio_write > > aio_write(aio buf) > > > > > > and for compression it would be: > > > > perf_mmap__push does: > > push(mmap buf) > > compress_push > > memcpy(compress buffer, mmapbuf) EXTRA copy > > record__pushfn > > record__write > > write(buf) > > > > perf_mmap__aio_push does: > > memcpy(aio buf, mmap buf) > > memcpy(compress buffer, mmapbuf) EXTRA copy > > push(aio buf) > > record__aio_pushfn > > record__aio_write > > aio_write(aio buf) > > > > > > side note: that actualy makes me think why do we even have > > perf_mmap__aio_push, > > it looks like we could copy the buf in the callback push function with no > > harm? > > Well, yes, perf_mmap__aio_push() can be avoided and perf_mmap__push() can be > used > as for serial as for AIO, moving all the specifics to record code from mmap.c, > like this: > > Serial > perf_mmap__push(, record__pushfn) > push(), possibly two times > record__pushfn() > if (-z) zstd_compress(map->base => map->data) <-- > compressing memcpy() > record__write(-z ? map->data, map->base) > AIO > record__aio_push() > perf_mmap__push(, record__aio_pushfn()) > push(), possibly two times > record__aio_pushfn() > if (-z) zstd_compress(map->base => map->aio.data[i]) <--- > compressing memcpy() > else memcpy(map->base => map->aio.data[i]) <--- plain > memcpy() > record__aio_write(map->aio.data[i]) > > So now it looks optimal as from performance and data loss reduction > perspective as from design perspective. What do you think? yes, that looks much better.. so we'd have record__pushfn for standard (serial) and record__aio_pushfn for AIO thanks, jirka
