Messages in this thread | | | Subject | Re: [PATCH v5 07/10] perf record: implement -z,--compression_level=n option and compression | From | Alexey Budankov <> | Date | Thu, 7 Mar 2019 18:56:55 +0300 |
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On 07.03.2019 18:26, Alexey Budankov wrote: > > On 07.03.2019 15:14, Jiri Olsa wrote: >> On Thu, Mar 07, 2019 at 11:39:46AM +0300, Alexey Budankov wrote: >>> >>> On 05.03.2019 15:25, Jiri Olsa wrote: >>>> On Fri, Mar 01, 2019 at 06:58:32PM +0300, Alexey Budankov wrote: >>>> >>>> SNIP >>>> >>>>> >>>>> /* >>>>> * Increment md->refcount to guard md->data[idx] buffer >>>>> @@ -350,7 +357,7 @@ int perf_mmap__aio_push(struct perf_mmap *md, void *to, int idx, >>>>> md->prev = head; >>>>> perf_mmap__consume(md); >>>>> >>>>> - rc = push(to, &md->aio.cblocks[idx], md->aio.data[idx], size0 + size, *off); >>>>> + rc = push(to, md->aio.data[idx], size0 + size, *off, &md->aio.cblocks[idx]); >>>>> if (!rc) { >>>>> *off += size0 + size; >>>>> } else { >>>>> @@ -556,13 +563,15 @@ int perf_mmap__read_init(struct perf_mmap *map) >>>>> } >>>>> >>>>> int perf_mmap__push(struct perf_mmap *md, void *to, >>>>> - int push(struct perf_mmap *map, void *to, void *buf, size_t size)) >>>>> + int push(struct perf_mmap *map, void *to, void *buf, size_t size), >>>>> + perf_mmap__compress_fn_t compress, void *comp_data) >>>>> { >>>>> u64 head = perf_mmap__read_head(md); >>>>> unsigned char *data = md->base + page_size; >>>>> unsigned long size; >>>>> void *buf; >>>>> int rc = 0; >>>>> + size_t mmap_len = perf_mmap__mmap_len(md); >>>>> >>>>> rc = perf_mmap__read_init(md); >>>>> if (rc < 0) >>>>> @@ -574,7 +583,10 @@ int perf_mmap__push(struct perf_mmap *md, void *to, >>>>> buf = &data[md->start & md->mask]; >>>>> size = md->mask + 1 - (md->start & md->mask); >>>>> md->start += size; >>>>> - >>>>> + if (compress) { >>>>> + size = compress(comp_data, md->data, mmap_len, buf, size); >>>>> + buf = md->data; >>>>> + } >>>>> if (push(md, to, buf, size) < 0) { >>>>> rc = -1; >>>>> goto out; >>>> >>>> when we discussed the compress callback should be another layer >>>> in perf_mmap__push I was thinking more of the layered/fifo design, >>>> like: >>>> >>>> normaly we call: >>>> >>>> perf_mmap__push(... push = record__pushfn ...) >>>> -> reads mmap data and calls push(data), which translates as: >>>> >>>> record__pushfn(data); >>>> - which stores the data >>>> >>>> >>>> for compressed it'd be: >>>> >>>> perf_mmap__push(... push = compressed_push ...) >>>> >>>> -> reads mmap data and calls push(data), which translates as: >>>> >>>> compressed_push(data) >>>> -> reads data, compresses them and calls, next push callback in line: >>>> >>>> record__pushfn(data) >>>> - which stores the data >>>> >>>> >>>> there'd need to be the logic for compressed_push to >>>> remember the 'next push' function >>> >>> That is suboptimal for AIO. Also compression is an independent operation that >>> could be applied on any of push stages you mean. >> >> not sure what you mean by suboptimal, but I think >> that it can still happen in subsequent push callback >> >>> >>>> >>>> but I think this was the original idea behind the >>>> perf_mmap__push -> it gets the data and pushes them for >>>> the next processing.. it should stay as simple as that >>> >>> Agree on keeping simplicity and, at the moment, there is no any push to the next >>> processing in the code so provided implementation fits as for serial as for AIO >>> at the same time sticking to simplicity as much as possibly. If you see something >>> that would fit better please speak up and share. >> >> I have to insist that perf_mmap__push stays untouched >> and we do other processing in the push callbacks > > What is about perf_mmap__aio_push()? > > Without compression it does > memcpy(), memcpy(), aio_push() > > With compression its does > memcpy_with_compression(), memcpy_with_compression(), aio_push() > > and deviation that increases amount of copy operations i.e. implementing three or more > is suboptimal in terms of runtime overhead and data loss decrease > > Compression for serial streaming can be implemented in push() callback. > AIO case would go with compression over a parameter in aio_push().
I meant compress_fn and comp_data parameters _for_ aio_push().
> So the both trace writing schemas could be optimally extended. > > ~Alexey > >> >> jirka >> >
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