On 2024/1/22 10:07, Gao Xiang wrote: > [你通常不会收到来自 [email protected] 的电子邮件。请访问 > https://aka.ms/LearnAboutSenderIdentification，以了解这一点为什么很重要] > > On 2024/1/20 22:55, Chunhai Guo wrote: >> Even with inplace decompression, sometimes extra temporary buffers are >> still needed for decompression. In low-memory scenarios, it would be >> better to try to allocate with GFP_NOWAIT on readahead first. That can >> help reduce the time spent on page allocation under memory pressure. >> >> There is an average reduction of 21% in page allocation time under > It would be better to add a table to show the absolute numbers too > (like what you did in the global pool commit.) If it's possible, there > is no need to send a update version for this, just reply the updated > commit message and I will update the commit manually.
The table below shows detailed numbers. The reduction I mentioned before was not accurate enough. Please help correct the improvement from 21% to 20.21%. +--------------+----------------+---------------+---------+ | | w/o GFP_NOWAIT | w/ GFP_NOWAIT | diff | +--------------+----------------+---------------+---------+ | Average (ms) | 3364 | 2684 | -20.21% | +--------------+----------------+---------------+---------+ Thanks, > > Otherwise it looks good to me, > > Thanks, > Gao Xiang > >> multi-app launch benchmark workload [1] on ARM64 Android devices running >> the 5.15 kernel with an 8-core CPU and 8GB of memory. >> >> [1] https://lore.kernel.org/r/[email protected] >> >> Suggested-by: Gao Xiang <[email protected]> >> Signed-off-by: Chunhai Guo <[email protected]> >> --- >> fs/erofs/compress.h | 5 ++--- >> fs/erofs/decompressor.c | 5 +++-- >> fs/erofs/decompressor_deflate.c | 19 +++++++++++++------ >> fs/erofs/decompressor_lzma.c | 17 ++++++++++++----- >> fs/erofs/zdata.c | 16 ++++++++++++---- >> 5 files changed, 42 insertions(+), 20 deletions(-) >> >> diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h >> index 279933e007d2..7cc5841577b2 100644 >> --- a/fs/erofs/compress.h >> +++ b/fs/erofs/compress.h >> @@ -11,13 +11,12 @@ >> struct z_erofs_decompress_req { >> struct super_block *sb; >> struct page **in, **out; >> - >> unsigned short pageofs_in, pageofs_out; >> unsigned int inputsize, outputsize; >> >> - /* indicate the algorithm will be used for decompression */ >> - unsigned int alg; >> + unsigned int alg; /* the algorithm for decompression */ >> bool inplace_io, partial_decoding, fillgaps; >> + gfp_t gfp; /* allocation flags for extra temporary buffers */ >> }; >> >> struct z_erofs_decompressor { >> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c >> index 1d65b9f60a39..ef2b08ec9830 100644 >> --- a/fs/erofs/decompressor.c >> +++ b/fs/erofs/decompressor.c >> @@ -111,8 +111,9 @@ static int z_erofs_lz4_prepare_dstpages(struct >> z_erofs_lz4_decompress_ctx *ctx, >> victim = availables[--top]; >> get_page(victim); >> } else { >> - victim = erofs_allocpage(pagepool, >> - GFP_KERNEL | __GFP_NOFAIL); >> + victim = erofs_allocpage(pagepool, rq->gfp); >> + if (!victim) >> + return -ENOMEM; >> set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE); >> } >> rq->out[i] = victim; >> diff --git a/fs/erofs/decompressor_deflate.c >> b/fs/erofs/decompressor_deflate.c >> index 4a64a9c91dd3..b98872058abe 100644 >> --- a/fs/erofs/decompressor_deflate.c >> +++ b/fs/erofs/decompressor_deflate.c >> @@ -95,7 +95,7 @@ int z_erofs_load_deflate_config(struct super_block *sb, >> } >> >> int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq, >> - struct page **pagepool) >> + struct page **pgpl) >> { >> const unsigned int nrpages_out = >> PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; >> @@ -158,8 +158,12 @@ int z_erofs_deflate_decompress(struct >> z_erofs_decompress_req *rq, >> strm->z.avail_out = min_t(u32, outsz, PAGE_SIZE - >> pofs); >> outsz -= strm->z.avail_out; >> if (!rq->out[no]) { >> - rq->out[no] = erofs_allocpage(pagepool, >> - GFP_KERNEL | __GFP_NOFAIL); >> + rq->out[no] = erofs_allocpage(pgpl, rq->gfp); >> + if (!rq->out[no]) { >> + kout = NULL; >> + err = -ENOMEM; >> + break; >> + } >> set_page_private(rq->out[no], >> Z_EROFS_SHORTLIVED_PAGE); >> } >> @@ -211,8 +215,11 @@ int z_erofs_deflate_decompress(struct >> z_erofs_decompress_req *rq, >> >> DBG_BUGON(erofs_page_is_managed(EROFS_SB(sb), >> rq->in[j])); >> - tmppage = erofs_allocpage(pagepool, >> - GFP_KERNEL | __GFP_NOFAIL); >> + tmppage = erofs_allocpage(pgpl, rq->gfp); >> + if (!tmppage) { >> + err = -ENOMEM; >> + goto failed; >> + } >> set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE); >> copy_highpage(tmppage, rq->in[j]); >> rq->in[j] = tmppage; >> @@ -230,7 +237,7 @@ int z_erofs_deflate_decompress(struct >> z_erofs_decompress_req *rq, >> break; >> } >> } >> - >> +failed: >> if (zlib_inflateEnd(&strm->z) != Z_OK && !err) >> err = -EIO; >> if (kout) >> diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c >> index 2dd14f99c1dc..6ca357d83cfa 100644 >> --- a/fs/erofs/decompressor_lzma.c >> +++ b/fs/erofs/decompressor_lzma.c >> @@ -148,7 +148,7 @@ int z_erofs_load_lzma_config(struct super_block *sb, >> } >> >> int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, >> - struct page **pagepool) >> + struct page **pgpl) >> { >> const unsigned int nrpages_out = >> PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; >> @@ -215,8 +215,11 @@ int z_erofs_lzma_decompress(struct >> z_erofs_decompress_req *rq, >> PAGE_SIZE - pageofs); >> outlen -= strm->buf.out_size; >> if (!rq->out[no] && rq->fillgaps) { /* deduped */ >> - rq->out[no] = erofs_allocpage(pagepool, >> - GFP_KERNEL | __GFP_NOFAIL); >> + rq->out[no] = erofs_allocpage(pgpl, rq->gfp); >> + if (!rq->out[no]) { >> + err = -ENOMEM; >> + break; >> + } >> set_page_private(rq->out[no], >> Z_EROFS_SHORTLIVED_PAGE); >> } >> @@ -258,8 +261,11 @@ int z_erofs_lzma_decompress(struct >> z_erofs_decompress_req *rq, >> >> DBG_BUGON(erofs_page_is_managed(EROFS_SB(rq->sb), >> rq->in[j])); >> - tmppage = erofs_allocpage(pagepool, >> - GFP_KERNEL | __GFP_NOFAIL); >> + tmppage = erofs_allocpage(pgpl, rq->gfp); >> + if (!tmppage) { >> + err = -ENOMEM; >> + goto failed; >> + } >> set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE); >> copy_highpage(tmppage, rq->in[j]); >> rq->in[j] = tmppage; >> @@ -277,6 +283,7 @@ int z_erofs_lzma_decompress(struct >> z_erofs_decompress_req *rq, >> break; >> } >> } >> +failed: >> if (no < nrpages_out && strm->buf.out) >> kunmap(rq->out[no]); >> if (ni < nrpages_in) >> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c >> index 692c0c39be63..a293de2a60ed 100644 >> --- a/fs/erofs/zdata.c >> +++ b/fs/erofs/zdata.c >> @@ -82,6 +82,9 @@ struct z_erofs_pcluster { >> /* L: indicate several pageofs_outs or not */ >> bool multibases; >> >> + /* L: whether extra buffer allocations are best-effort */ >> + bool besteffort; >> + >> /* A: compressed bvecs (can be cached or inplaced pages) */ >> struct z_erofs_bvec compressed_bvecs[]; >> }; >> @@ -964,7 +967,7 @@ static int z_erofs_read_fragment(struct super_block *sb, >> struct page *page, >> } >> >> static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, >> - struct page *page) >> + struct page *page, bool ra) >> { >> struct inode *const inode = fe->inode; >> struct erofs_map_blocks *const map = &fe->map; >> @@ -1014,6 +1017,7 @@ static int z_erofs_do_read_page(struct >> z_erofs_decompress_frontend *fe, >> err = z_erofs_pcluster_begin(fe); >> if (err) >> goto out; >> + fe->pcl->besteffort |= !ra; >> } >> >> /* >> @@ -1280,7 +1284,11 @@ static int z_erofs_decompress_pcluster(struct >> z_erofs_decompress_backend *be, >> .inplace_io = overlapped, >> .partial_decoding = pcl->partial, >> .fillgaps = pcl->multibases, >> + .gfp = pcl->besteffort ? >> + GFP_KERNEL | __GFP_NOFAIL : >> + GFP_NOWAIT | __GFP_NORETRY >> }, be->pagepool); >> + pcl->besteffort = false; >> >> /* must handle all compressed pages before actual file pages */ >> if (z_erofs_is_inline_pcluster(pcl)) { >> @@ -1785,7 +1793,7 @@ static void z_erofs_pcluster_readmore(struct >> z_erofs_decompress_frontend *f, >> if (PageUptodate(page)) >> unlock_page(page); >> else >> - (void)z_erofs_do_read_page(f, page); >> + (void)z_erofs_do_read_page(f, page, !!rac); >> put_page(page); >> } >> >> @@ -1806,7 +1814,7 @@ static int z_erofs_read_folio(struct file *file, >> struct folio *folio) >> f.headoffset = (erofs_off_t)folio->index << PAGE_SHIFT; >> >> z_erofs_pcluster_readmore(&f, NULL, true); >> - err = z_erofs_do_read_page(&f, &folio->page); >> + err = z_erofs_do_read_page(&f, &folio->page, false); >> z_erofs_pcluster_readmore(&f, NULL, false); >> z_erofs_pcluster_end(&f); >> >> @@ -1847,7 +1855,7 @@ static void z_erofs_readahead(struct readahead_control >> *rac) >> folio = head; >> head = folio_get_private(folio); >> >> - err = z_erofs_do_read_page(&f, &folio->page); >> + err = z_erofs_do_read_page(&f, &folio->page, true); >> if (err && err != -EINTR) >> erofs_err(inode->i_sb, "readahead error at folio %lu >> @ nid %llu", >> folio->index, EROFS_I(inode)->nid);
